Combined metering apparatus

ABSTRACT

This invention provides a combined metering apparatus in which the convey efficiency of a target metering object from an upper-stage hopper to a lower-stage hopper is improved. For this purpose, the direction in which a bottom plate 33 of a pool hopper 25 is moved to open the lower open surface of a cylindrical body 26 and the direction in which a bottom plate 43 of a lower-stage metering hopper 35 is moved to close the lower open surface of a cylindrical body 36 are set the same. Also, the direction in which the bottom plate 43 of the metering hopper 35 is moved to open the lower open surface of the cylindrical body 36 and the direction in which a bottom plate 59 of a lower-stage timing hopper 50 is moved to open the lower open surface of a cylindrical body 51 are set the same. Hence, when the bottom plate of the lower-stage hopper is moved in the closing direction, the bottom plate of the upper-stage hopper is moved in the opening direction almost simultaneously, so that the target metering object in the upper-stage hopper can be transferred to the lower-stage hopper efficiently.

TECHNICAL FIELD

The present invention relates to a combined metering apparatus formetering a plurality of target metering objects supplied from a worktable or the like and having varied weights, combining the targetmetering objects in unit target weights, and discharging the combinedtarget metering objects and, more particularly, to a combined meteringapparatus for separately measuring the weights of a plurality of targetmetering objects separately introduced into a plurality of meteringcontainers by using a plurality of metering means, in particular loadcells, combining the plurality of target metering objects supplied fromthe plurality of metering containers to have a predetermined weightafter the measurement, and discharging the combined target meteringobjects.

BACKGROUND ART

A combined metering apparatus is conventionally used to efficientlydischarge food and the like having varied weights in the form of a batchhaving a target weight.

Generally, in the combined metering apparatus of this type, targetmetering objects, e.g., food, are supplied from a plurality of poolhoppers to a plurality of metering hoppers arranged below the poolhoppers, and are metered. The combination of the target metering objectshaving a weight close or equal to the target weight is selected based onthe metering results of the respective metering hoppers. The targetmetering objects selected to constitute this combination are dischargedfrom the respective metering hoppers and are collected together.

As a method of measuring the weight of a target metering object, one isavailable which converts the deformation of an elastic body into achange in electric resistance. A load detector based on this principleis generally called a load cell, and is sometimes called a strain gaugetype load cell.

Particularly, a load cell 200 shown in FIG. 36 is called a load beam ordual beam type load cell. This load cell 200 is suitable for measuring asmall weight and has good dynamic characteristics with a simple, compactstructure.

In this load cell 200, four strain gauges 202c are mounted to an elasticbody (magnetostrictive body) 202d to which a load is applied. The straingauges 202c constitute a Wheatstone bridge circuit. A mount side 202a ofthe elastic body 202d is fixed to the base body and a load is applied toa load side 202b. An output resulted from a change in resistanceproportional to the load is detected.

As a metering apparatus utilizing a load cell, one as shown in FIG. 37is available which is disclosed in Jpn. Pat. Appln. KOKAI PublicationNo. 3-123233 to the same applicant as that of this application. In thismetering apparatus, the mount side of a load cell 231 is fixed to a basebody 232, and one base plate 233 is mounted on the load side of the loadcell 231.

A metering hopper 234 for storing and metering a target metering object,and a drive portion 236 for opening/closing a discharge door 235,through which the target metering object is stored in and dischargedfrom the metering hopper 234, are attached to the base plate 233.

When metering a target metering object, the discharge door 235 of themetering hopper 234 is closed, and the target metering object isintroduced into the metering hopper 234. When metering is ended, thedischarge door 235 is opened, and the target metering object isdischarged from the metering hopper 234.

Similarly, as a metering apparatus utilizing a load cell, one shown inFIG. 38 is available which is disclosed in Jpn. Pat. Appln. KOKAIPublication No. 4-363630 to the same applicant as that of thisapplication.

In this metering apparatus, the mount side of a load cell 237 is fixedto a base body 238, and a cylindrical member 239 is mounted on the loadside of the load cell 237 in place of a metering hopper having adischarge door as described above.

An opening/closing member 240 for storing and discharging the targetmetering object is provided under the cylindrical member 239. Theopening/closing member 240 is moved in the horizontal direction by amoving mechanism 243 connected to a piston 242 of an air cylinder 241.

When metering the target metering object, the opening/closing member 240on the lower side of the cylindrical member 239 is closed, and thetarget metering object is introduced into the cylindrical member 239.When metering is ended, the opening/closing member 240 is moved to openthe lower side of the cylindrical member 239, so that the targetmetering object is discharged.

In the metering apparatus disclosed in Jpn. Pat. Appln. KOKAI No.3-123233, as the moving direction of the drive portion 236 is the sameas the load direction of the load cell 231, the opening/closingoperation of the discharge door 235 of the metering hopper 234 causesthe load of the load cell 231 to fluctuate.

The drive portion 236 is mounted on the load side of the load cell 231.As a tube and the like for supplying air serving as the drive source tothe drive portion 236 is connected between the load side of the loadcell 231 and the base body 232, when an air pressure is applied, theload of the load cell 231 is adversely affected.

In the metering apparatus disclosed in Jpn. Pat. Appln. KOKAI No.4-36360, as the moving direction of the air cylinder 241 isperpendicular to the load direction of the load cell 237, the movementof the air cylinder 241 will not cause the load of the load cell 237 tofluctuate. When the target metering object is to be metered, however,the cylindrical member 239 and the moving mechanism 243 must be keptdisconnected from each other.

More specifically, in the metering state, if the cylindrical member 239mounted on the load side of the load cell 237 and the moving mechanism243 mounted on the base body 238 are in contact with each other, anaccurate load does not act on the load cell 237, and erroneous meteringmay be performed.

For this reason, the moving mechanism 243 must be able to bedisconnected from the cylindrical member 239 when performing metering,leading to a complicated structure.

Regarding a hopper used in the combined metering apparatus describedabove, the open surface at its bottom portion is opened/closed with apivot gate. When a target metering object containing water or oil andthus having tackiness is supplied to this hopper, even if the hopper isopened by pivoting the gate, the target metering object sometimesattaches to the gate and is not discharged, or is caught in the gatewhen the gate is closed.

In order to solve these problems, a combined metering apparatus isconventionally available in which each of the pool hopper and themetering hopper is constituted by a cylindrical body having upper andlower open ends and a bottom plate which is formed to be larger than thelower open surface of the cylindrical body and is slidably movedrelative to the cylindrical body, thereby opening/closing the lower opensurface of the cylindrical body.

FIGS. 39A, 39B, and 39C show a combined metering apparatus from a sidesurface. This combined metering apparatus has a hopper, the cylindricalbody of which is slid with respect to the bottom plate. A cylindricalbody 3 having upper and lower open ends is placed on a horizontal bottomplate 2 mounted on a front surface 1a of a housing 1 to constitute apool hopper 4. This cylindrical body 3 is moved back and forth (in theright-to-left direction in FIGS. 39A, 39B, and 39C) by a cylinder 5 inthe housing 1, thereby opening/closing the lower open surface of thecylindrical body.

A metering hopper 9 constituted by a bottom plate 7 and a cylindricalbody 8 is arranged below the pool hopper 4. The bottom plate 7 issupported by a metering unit 6 (load cell) fixed to the housing 1 toextend forward from the housing 1. The cylindrical body 8 has upper andlower open ends and is placed on the bottom plate 7.

While the lower open surface of the pool hopper 4 is completely closedwith the cylindrical body 8 of the metering hopper 9 and the bottomplate 7, the metering hopper 9 is located immediately under thecylindrical body 3 of the pool hopper 4 which has moved forward to aposition to completely open the lower open surface. From this position,the metering hopper 9 is moved forward by a cylinder 10 in the housing 1to open the lower open surface of the pool hopper 4.

In the combined metering apparatus having this arrangement, as shown inFIG. 39A, while target metering objects are stored in the pool hopper 4and the metering hopper 9, assume that the target metering object in themetering hopper 9 is selected to constitute the combination. Then, asshown in FIG. 39B, the cylindrical body 8 is moved forward (to the rightin FIG. 39B) by the cylinder 10 to open its lower open surface from theright to the left in FIG. 39B, and the target metering object on thebottom plate 7 is discharged downward as it is scraped by the inner leftedge of the lower open surface of the cylindrical body 8. Thereafter,the cylindrical body 8 is returned to the left by the cylinder 10.

In order to supply a next target metering object to the metering hopper9 which is emptied, the cylinder 5 is driven to move the cylindricalbody 3 of the pool hopper 4 to the right, as shown in FIG. 39C, and thetarget metering object on the bottom plate 2 is stored in the meteringhopper 9 as it is scraped with the inner left edge of the lower opensurface of the cylindrical body 3.

FIGS. 40A, 40B, and 40C show an example of a combined metering apparatusin which cylindrical bodies 3 and 8 of a pool hopper 4' and a meteringhopper 9' are fixed, and bottom plates 2' and 7' are moved by cylinders5 and 10.

In this case, the cylindrical bodies 3 and 8 of the pool hopper 4' andmetering hopper 9' are fixed at such positions where the lower opensurface of the cylindrical body 3 coincides with the upper open surfaceof the cylindrical body 8.

As shown in FIG. 40A, while target metering objects are stored in thepool hopper 4' and metering hopper 9', when the target metering objectin the metering hopper 9' is selected to constitute the combination, asshown in FIG. 40B, the bottom plate 7' of the metering hopper 9' ismoved to the left, and the target metering object on the bottom plate 7'is discharged downward as it is scraped by the inner left edge of thecylindrical body 8. Thereafter, the bottom plate 7' is returned to theright.

In order to newly supply a target metering object in the metering hopper9' which is emptied by this discharge, as shown in FIG. 40C, the bottomplate 2' of the pool hopper 4' is moved to the left, so that the targetmetering object on the bottom plate 2' is discharged into the meteringhopper 9' as it is scraped by the inner left edge of the cylindricalbody 3. In the metering apparatus as shown in FIGS. 40A, 40B, and 40C,the weights of the bottom plate 7' of the metering hopper 9' and thecylinder 10 and the load of the target metering object act on themetering unit 6.

In this manner, in the combined metering apparatus whose hopper isconstituted by the cylindrical body having upper and lower open ends andthe bottom plate which is slidably moved relative to the cylindricalbody to open/close the lower open surface of the cylindrical body, sincethe inner wall surface of the hopper is substantially upright, thetarget metering object will not easily attach to it. Also, since thelower open surface of the hopper is opened/closed by the horizontalmovement of the bottom plate, the target metering object on the bottomplate can be discharged as it is scraped by the lower edge of thecylindrical body, so that the target metering object having tackinesscan be discharged reliably.

In recent years, in the combined metering apparatus having the abovearrangement, a strong demand has arisen for more efficient discharge ofthe target metering object.

In order to meet this demand, the target metering object must besupplied from the pool hopper to the metering hopper at a higher speed.

Even if the moving speed of the cylindrical body or its bottom plate issimply increased, however, the lower open surface may be closed beforethe target metering object is completely discharged from the hopper.

Therefore, it is considered that the supply speed of the target meteringobject into the metering hopper be increased by overlapping the periodrequired for closing the lower open surface of the metering hopper andthe period required for opening the lower open surface of the poolhopper to supply the target metering object to the metering hopper.

In the combined metering apparatus shown in FIGS. 39A, 39B, and 39Cdescribed above, however, if the cylindrical body 3 of the pool hopper 4is moved to the right (in the opening direction) before the cylindricalbody 8 of the metering hopper 9 that has discharged the target meteringobject is not completely returned to the predetermined position on thebottom plate 7, the first target metering object discharged from thepool hopper 4 will undesirably fall outside the metering hopper 9.

Also, in the combined metering apparatus shown in FIGS. 40A, 40B, and40C described above, if the bottom plate 2' of the pool hopper 4' ismoved to the left (in the opening direction) before the bottom plate 7'of the metering hopper that has discharged the target metering object isnot returned to the position to completely close the lower open surfaceof the cylindrical body 8, the first target metering object dischargedfrom the pool hopper 4' will be undesirably discharged below themetering hopper through the interior of the metering hopper 9'.

In this manner, in the conventional combined metering apparatusesdescribed above, the convey efficiency of the target metering objectbetween the upper and lower hoppers cannot be further increased, and theoperational efficiency of the apparatus as a whole cannot thus beincreased.

A combined metering apparatus is conventionally available in which eachof the pool hopper and the metering hopper is constituted by acylindrical body having upper and lower open ends so that the targetmetering object received from above will not easily attach to the innerwall surface, and a bottom plate which is slidably moved while its uppersurface is in contact with the lower end of this cylindrical body,thereby opening/closing the lower open surface of the cylindrical body.

FIGS. 41A, 41B, and 41C are side views schematically showing a combinedmetering apparatus which is constituted by such slidable hoppers.

In FIGS. 41A, 41B, and 41C, pool hoppers 2 are arranged in a horizontalarray (in a direction perpendicular to the surface of the drawing) onthe upper stage of the front surface of a housing 1 of the combinedmetering apparatus, and metering hoppers 7 are arranged below therespective pool hoppers 2.

Each pool hopper 2 is constituted by a cylindrical body 3 having anupper open surface slightly larger than its lower open surface, and abottom plate 4 which is larger than the lower open surface and is slidback and forth with its upper surface being in contact with the lowerend of the cylindrical body 3, thereby opening/closing the lower opensurface of the cylindrical body 3. The cylindrical body 3 is fixed witha support member 5 at a position remote from the front surface of thehousing 1 by a predetermined distance, and the bottom plate 4 issupported by a drive shaft 6a projecting from a drive unit 6 (e.g., acylinder unit) in the housing 1.

Similarly as the pool hopper 2, each metering hopper 7 is constituted bya cylindrical body 8 having an upper open surface larger than its loweropen surface, and a bottom plate 9 which is larger than the lower opensurface and is slid back and forth with its upper surface being incontact with the lower end of the cylindrical body 8, therebyopening/closing the lower open surface of the cylindrical body 8.

The cylindrical body 8 is fixed by a support member 10 at a positionwhere the center of its upper open surface coincides with the center ofthe lower open surface of the cylindrical body 3 of the pool hopper 2.

The bottom plate 9 is supported by a drive shaft 11a projecting from adrive unit 11 (e.g., a cylinder unit) in the housing 1.

At least the bottom plate 9 and the drive unit 11 are supported by ametering unit (not shown) provided in the housing 1, and a targetmetering object placed on the bottom plate 9 is detected by thismetering unit.

In the combined metering apparatus having this arrangement, while targetmetering objects are stored in the pool hopper 2 and the metering hopper7, as shown in FIG. 41A, when the target metering object in the meteringhopper 7 is selected to constitute the combination, the bottom plate 9of the metering hopper 7 is driven by the drive unit 11 to move backward(toward the housing 1), as shown in FIG. 41B.

Hence, the target metering object on the bottom plate 9 is dischargeddownward as it is scraped by the lower end portion of the inner wall ofthe cylindrical body 8 on the housing 1 side, and is collected by acollecting means (not shown).

When the bottom plate 9 is moved to a position to completely open thelower open surface of the cylindrical body 8 and the target meteringobject in the metering hopper 7 is completely discharged, the bottomplate 9 is moved forward, i.e., in a direction to separate from thefront surface of the housing, thereby closing the lower open surface ofthe cylindrical body 8.

In order to newly supply the target metering object to the meteringhopper 7 which is emptied by this discharge, the bottom plate 4 of thepool hopper 2 is moved backward, as shown in FIG. 41C.

Hence, the target metering object on the bottom plate 4 falls into thecylindrical body 8 of the metering hopper 7 below the bottom plate 4 asit is scraped by the lower end portion of the inner wall of thecylindrical body 3 on the housing 1 side, is loaded on the bottom plate9 that closes the lower open surface of the cylindrical body 8, and ismetered.

However, the combined metering apparatus constituted by the conventionalslidable bottom plate type hoppers has problems as follows.

(1) When the bottom plate 4 of the upper-stage pool hopper 2 is moved inthe opening direction (toward the housing 1), the target metering objecton the bottom plate 4 is dragged by the bottom plate 4 to be dischargedin the moving direction of the bottom plate 4 slightly obliquely. Thus,part of the target metering object on the bottom plate 4 is sometimesundesirably discharged outside the upper open surface of the cylindricalbody 8 of the lower-stage metering hopper 7.

In order to solve this, the vertical gap between the lower open surfaceof the cylindrical body 3 of the upper-stage pool hopper 2 and the upperopen surface of the cylindrical body 8 of the lower-stage meteringhopper 7 may be decreased, or the ratio in size of the lower opensurface of the cylindrical body 3 of the upper-stage pool hopper 2 tothe upper open surface of the cylindrical body 8 of the lower-stagemetering hopper 7 may be further increased.

However, the gap between the lower open surface of the upper-stagecylindrical body 3 and the upper open surface of the lower-stagecylindrical body 8 must be sufficiently large so as not to interferewith the movement of the bottom plate 4. There is a limitation todecrease this gap.

When cylindrical bodies having the same shape are employed as the poolhopper and the metering hopper, in order to further increase the ratioin size of the lower open surface of the upper-stage cylindrical body 3to the upper open surface of the lower-stage cylindrical body 8, asdescribed above, the ratio in size of the upper open surface to thelower open surface of the cylindrical body must be increased.

If, however, the ratio in size of the upper open surface to the loweropen surface of the cylindrical body is increased, the inclination ofthe inner wall portion of the cylindrical body is decreased at leastpartially. Then, a target metering object having tackiness cannot bedischarged smoothly.

When the cylindrical body 8 of the lower-stage hopper is made entirelylarger than the cylindrical body 3 of the upper-stage hopper,cylindrical bodies having different shapes must be prepared for the poolhopper and the metering hopper. This leads to a considerableinconvenience in terms of component management and maintenance.

(2) In the method of slidably moving the bottom plate of each hopper bydirectly supporting it with the drive shaft of the drive unit, when thetarget metering object is stored, its load directly acts on the driveshaft. As the bottom plate vibrates vertically, the drive shaft is alsovibrated. Since the movement of the drive shaft is adversely affected bythe drive unit, the bottom plate cannot be moved smoothly, and thetarget metering object cannot be conveyed smoothly.

For this reason, if the rigidity of the bottom plate and the drive shaftis increased and the bottom plate and the drive shaft are fixed firmly,the bottom plate cannot be removed easily. Then, the bottom plate whichcan be soiled easily must be cleaned at the site where the meteringapparatus is installed, and the type of the target metering objectcannot be changed readily, leading to an inconvenience.

(3) As described above, in the combined metering apparatus havingcylindrical bodies, the outer walls of which are upright down to theirlower ends, as the bottom plate is moved in the opening direction, ifsmall tailings of the target metering object attaching on the bottomplate are moved outside the cylindrical body, they are scraped by thelower end of the upright outer wall of the cylindrical body when thebottom plate closes in the closing direction. The tailings are easilydeposited on the lower portion of the outer wall surface of thecylindrical body. The deposited target metering object may be dried anddenatured and undesirably discharged to the lower hopper, or may fallinto a hopper undergoing metering, thus causing a metering error.

In addition, in the combined metering apparatus described above,portions, e.g., the convey table of the supply unit, the hoppers, thecollecting chute, and the like, which are brought into contact with thetarget metering object, are formed by working a stainless steel plate,and these components can be removed from the apparatus body tofacilitate cleaning.

When changing the type of the target metering object, after the conveytable, the hoppers, the collecting chute, and the like are removed fromthe entire apparatus and cleaned, they are sterilized by boiling, andare mounted into the apparatus.

However, this conventional combined metering apparatus has problems asfollows.

(1) Most of the components, e.g., the supply unit, the hoppers, thecollecting chute, and the like, which are brought into contact with thetarget metering object, are made of stainless steel which is heavy. In acombined metering apparatus that uses many hoppers in order to increasethe combination precision, the weight of the entire apparatus isincreased considerably.

(2) As the convey table and the gates of the hoppers are heavy,mechanisms for vibrating or opening/closing them are increased in size.This leads to a large drive energy and large noise during driving.

(3) Since the stainless steel plate is expensive itself and the conveytable, the hoppers, and the collecting chute are formed by bending andwelding it, the cost of the entire apparatus cannot be decreased. Inparticular, when the surfaces of these components that are brought intocontact with the target metering object are formed with recesses andprojections so that the target metering object having tackiness will notattach to them, the working cost is remarkably increased.

(4) If only cleaning at room temperature is performed, various bacteriawill proliferate. Thus, sterilization by boiling is required, leading toa high cleaning cost.

For these reasons, these constituent components may be made of asynthetic resin. With the synthetic resin, however, scratches can beeasily formed on the surfaces of the components. It is difficult tocompletely sterilize the bacteria proliferated in the scratches bycleaning at room temperature. Sterilization by boiling cannot beperformed since the synthetic resin can be easily deformed at hightemperatures. Thus, a serious sanitary problem arises.

DISCLOSURE OF INVENTION

The present invention has been made in order to solve the aboveproblems, and has as its first object to provide a combined meteringapparatus having high measuring precision with a simple structure.

In addition to the first object, it is the second object of the presentinvention to provide a combined metering apparatus in which the conveyefficiency of the target metering object from the upper-stage hopper tothe lower-stage hopper is increased, thereby increasing the operationalefficiency.

In addition to the first object, it is the third object of the presentinvention to provide a combined metering apparatus capable of conveyingthe target metering object from the upper-stage hopper to thelower-stage hopper smoothly and reliably.

In addition to the first object, it is the fourth object of the presentinvention to provide a combined metering apparatus whose base body doesnot require interior cleaning.

According to the present invention, there is provided a combinedmetering apparatus comprising:

supply means for supplying target metering objects;

a plurality of pool hoppers for separately receiving the target meteringobjects supplied by the supply means, the plurality of pool hoppersbeing arranged in a horizontal direction in sets each consisting of afirst cylindrical body having upper and lower open end portions, and afirst bottom plate slidable to selectively open/close the lower open endportion of the first cylindrical body;

a plurality of metering hoppers for receiving the target meteringobjects separately falling from the plurality of pool hoppers, theplurality of metering hoppers being arranged in sets on a lower stageside of the plurality of pool hoppers to correspond thereto, each of thesets consisting of a second cylindrical body having upper and lower openend portions, and a second bottom plate slidable to selectivelyopen/close the lower open end portion of the second cylindrical body;

a plurality of metering means provided in association with the pluralityof metering hoppers to separately meter the target metering objectsreceived in the plurality of metering hoppers and to output electricsignals, each of the metering means including

(a) a base body,

(b) a load cell, a mount side of which is mounted on the base body,

(c) a cylindrical member mounted on a load side of the load cell andhaving a receiving port at an upper portion thereof to receive thetarget metering object and a discharge port at a lower portion thereofto discharge the target metering object therethrough,

(d) an opening/closing member mounted on the load side of the load cellto open/close the discharge port, and

(e) a drive portion mounted on the load side of the load cell to drivethe opening/closing member substantially horizontally;

selecting means for selecting a combination of the target meteringobjects providing a predetermined metered value in the plurality ofmetering hoppers in accordance with the electric signals from theplurality of metering means; and

means for collecting and discharging the target metering objects fallingfrom corresponding ones of the plurality of metering hoppers inaccordance with the combination of the target metering objects selectedby the selecting means.

According to the present invention, there is also provided a combinedmetering apparatus comprising:

supply means for supplying target metering objects;

a plurality of pool hoppers for separately receiving the target meteringobjects supplied by the supply means, the plurality of pool hoppersbeing arranged in a horizontal direction in sets each consisting of afirst cylindrical body having upper and lower open end portions, and afirst bottom plate slidable to selectively open/close the lower open endportion of the first cylindrical body;

a plurality of metering hoppers for receiving the target meteringobjects separately falling from the plurality of pool hoppers, theplurality of metering hoppers being arranged in sets on a lower stageside of the plurality of pool hoppers to correspond thereto, each of thesets consisting of a second cylindrical body having upper and lower openend portions, and a second bottom plate slidable to selectivelyopen/close the lower open end portion of the second cylindrical body;

a plurality of metering means provided in association with the pluralityof metering hoppers to separately meter the target metering objectsreceived in the plurality of metering hoppers and to output electricsignals;

selecting means for selecting a combination of the target meteringobjects providing a predetermined metered value in the plurality ofmetering hoppers in accordance with the electric signals from theplurality of metering means;

a plurality of timing hoppers for receiving the target metering objectsfalling from corresponding ones of the plurality of metering hoppers inaccordance with the combination of the target metering objects selectedby the selecting means, the plurality of timing hoppers being arrangedin sets on a lower stage side of the plurality of metering hoppers tocorrespond thereto, each of the sets consisting of a third cylindricalbody having upper and lower open end portions, and a third bottom plateslidable to selectively open/close the lower open end portion of thethird cylindrical body at a timing delayed from opening/closingoperations of other third cylindrical bodies by a predetermined periodof time; and

means for collecting and discharging the target metering objects fallingfrom the plurality of timing hoppers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective views respectively showing the outerappearances of the first embodiment and its modification of the presentinvention;

FIG. 2 is a front view of the first embodiment;

FIG. 3 is a side view of the first embodiment;

FIG. 4 is a perspective view of the main part of the first embodiment;

FIG. 5 is a perspective view of the main part of the first embodiment;

FIG. 6 is a perspective view of the main part of the first embodiment;

FIG. 7 is a functional block diagram showing the arrangement of acontrol unit of the first embodiment;

FIGS. 8A to 8D are schematic front views for explaining the overalloperation of the first embodiment;

FIGS. 9A to 9G are schematic side views for explaining the operations ofbottom plates of hoppers of the first embodiment that are arrangedvertically;

FIGS. 10A and 10B are schematic diagrams for explaining thecollecting/discharging operation of the first embodiment;

FIG. 11 is a front view showing the main part of the second embodimentof the present invention;

FIG. 12 is a plan view showing the main part of the second embodiment;

FIG. 13 is a front view showing the operation of the main part of thesecond embodiment;

FIG. 14 is a perspective view showing the main part of the secondembodiment;

FIG. 15 is a perspective view of the main part of the third embodiment;

FIG. 16 is a perspective view of the main part of the third embodimentseen from the lower surface side;

FIG. 17 is a schematic front view of the main part of the thirdembodiment;

FIG. 18 is a perspective view of the main part of the third embodiment;

FIG. 19 is a perspective view of the main part of the third embodimentseen from the lower surface side;

FIG. 20 is a schematic side view showing the positional relationshipamong hoppers that are arranged vertically;

FIGS. 21A to 21G are schematic side views for explaining the operationsof bottom plates of the hoppers of the third embodiment that arearranged vertically;

FIGS. 22A and 22B are schematic side views for explaining the operationof the third embodiment;

FIG. 23 is a front view showing the fourth embodiment of the presentinvention;

FIG. 24 is a plan view showing the fourth embodiment of the presentinvention;

FIG. 25 is a front view showing the operation of the fourth embodimentof the present invention;

FIG. 26 is a schematic side view of the fifth embodiment of the presentinvention;

FIG. 27 is a side view of a circular feeder of the fifth embodiment;

FIG. 28 is a side view of a linear feeder of the fifth embodiment;

FIG. 29 is a perspective view of an intermediate hopper of the fifthembodiment;

FIG. 30 is a perspective view of the intermediate hopper of the fifthembodiment;

FIG. 31 is a perspective view of the main part of the fifth embodiment;

FIG. 32 is a perspective view of a metering hopper of the fifthembodiment;

FIG. 33 is a perspective view of the metering hopper of the fifthembodiment;

FIG. 34 is a perspective view of chute plates of the fifth embodiment;

FIG. 35 is a perspective view of a discharge hopper of the fifthembodiment;

FIG. 36 is a schematic view showing the outline of a load cell;

FIG. 37 is a front view showing a prior art;

FIG. 38 is a front view showing a prior art;

FIGS. 39A, 39B, and 39C are functional block diagrams showing thearrangement of a control unit of the fourth embodiment;

FIGS. 40A, 40B, and 40C are schematic front views for explaining theoverall operation of the fourth embodiment; and

FIGS. 41A, 41B, and 41C are schematic side views for explaining thearrangement and operation of a conventional apparatus.

BEST MODE OF CARRYING OUT THE INVENTION

Several embodiments of the present invention will be described withreference to the accompanying drawings.

FIGS. 1A to 6 show the outer appearance of a combined metering apparatus20 according to the first embodiment, which meters target meteringobjects having tackiness, and the schematic structures of its respectiveportions.

In FIGS. 1A to 6, a substantially rectangular parallelepiped housing 22is supported on a base table 21 of the combined metering apparatus 20.

A plurality of (ten in this embodiment) electromagnetic vibrating units23 are arranged in an array at the upper portion in the interior of thehousing 22 in the widthwise direction of the housing 22, and vibratingshafts 23a of the respective vibrating units 23 project from an uppersurface 22a of the housing 22.

Convey troughs 24 each formed into the shape of a gutter are mounted onthe upper ends of the respective vibrating shafts 23a to be directed tothe front side of the housing 22.

A target metering object is supplied to each convey trough 24 through awork table 19 shown in FIG. 1B, through a chute or a bucket conveyor(not shown), or manually.

Upon energization for a predetermined period of time, each vibratingunit 23 vibrates the corresponding convey trough 24 back and forthslightly upwardly with respect to the front surface side of the housing22, to convey the target metering objects on the convey troughs 24 tothe front end side by vibration.

Hollow square-cylindrical pool hoppers 25 having substantiallyrectangular upper and lower open ends are horizontally arranged in anarray below the front ends of the respective convey troughs 24.

Each pool hopper 25 is constituted by a cylindrical body 26 made of asynthetic resin and having upper and lower open ends, and a bottom plate33 to be described later, as shown in FIG. 4. As used throughout thespecification and claims, the term cylindrical body is meant toencompass tubular members which have circular or any polygonalcross-sectional configuration, as is apparent from the drawings whichshow generally square cross-sectional configurations.

An upper open surface 26a of the cylindrical body 26 is formed to beslightly larger than a lower open surface 26b. Flanges 26c and 26dextend from the front and rear edges of the lower open surface 26b. Twolocking holes 27 are formed in one flange 26c.

The pool hoppers 25 are supported by frames 28 mounted to the right andleft portions of a front surface 22b of the housing 22.

More specifically, five pin fixing plates 29 are mounted on the innerside of a front plate 28a of each frame 28 at predetermined intervals.

Two locking pins 31 extend upright on each pin fixing plate 29 at thesame gap as that of the locking holes 27 of the cylindrical body 26 ofthe pool hopper 25.

A pair of guide shafts 32 are bridged between the front plate 28a of theframe 28 and the front surface 22b of the housing 22 to extend parallelto each other on the two sides of each pair of locking pins 31.

A bottom plate 33 is supported on each pair of guide shafts 32.

Each bottom plate 33 is engaged with one guide shaft 32 on its lowersurface side and supported to be slidable back and forth.

The cylindrical body 26 of each pool hopper 25 is supported to be placedon the bottom plate 33 such that its flange 26c where the locking holes27 are formed faces the front, and the locking holes 27 are locked bythe pair of locking pins 31.

Each bottom plate 33 is formed into a substantially rectangular shapehaving a size enough to close the lower open surface of the cylindricalbody 26 of the pool hopper 25, and its rear portion on its one sideportion is detachably coupled to the distal end of a cylinder shaft 34aprojecting from the front surface 22b of the housing 22.

Each cylinder 34 provided in the housing 22 constitutes the firstopening/closing drive unit of this embodiment. The cylinder 34 retractsthe corresponding bottom plate 33 backward until the front end of thebottom plate 33 comes to a position below the flange 26d of thecylindrical body 26, thereby opening the lower open surface 26b of thecylindrical body 26. Inversely, the cylinder 34 pushes the bottom plate23 forward until the front end of the bottom plate 23 comes to aposition below the flange 26c of the cylindrical body 26, therebyclosing the lower open surface 26b of the cylindrical body 26.

Metering hoppers 35 are horizontally arranged in an array below therespective pool hoppers 25.

Each metering hopper 35 is constituted by a cylindrical body 36 havingthe same shape as that of the cylindrical body 26 of the pool hopper 25,and a bottom plate 43 having the same shape as that of the bottom plate33 of the pool hopper 25.

The cylindrical body 36 of the metering hopper 35 is supported to bealigned in the reverse direction with respect to the cylindrical body 26of the pool hopper 25 at a position where its upper open surface 36aopposes to overlap the lower open surface 26b of the cylindrical body 26of the pool hopper 25, so that it can receive the target metering objectdischarged from the cylindrical body 26 of the pool hopper 25.

Two locking holes 37 formed in one flange 36c, among flanges 36c and 36dprovided on the front and rear sides of a lower open surface 36b of thecylindrical body 36, are supported by a corresponding hopper support 40supported by the front surface 22b of the housing 22.

Two locking pins 41 are provided to project upright on the upper surfaceof the hopper support 40, and a pair of guide shafts 42 are mounted onthe two end portions of the hopper support 40 to extend forward parallelto each other at a gap slightly larger than that of the locking pins 41.

A bottom plate 43 guided by the pair of guide shafts 42 to be slidableback and forth is supported on the pair of guide shafts 42.

The cylindrical body 36 of each metering hopper 35 is so supported as tobe placed on the bottom plate 43 while its locking holes 37 are lockedby the pair of locking pins 41.

Each bottom plate 43 is formed into a rectangle having a size enough toclose the lower open surface of the cylindrical body 36 of the meteringhopper 35, in completely the same manner as the bottom plate 33 of thepool hopper 25.

The rear portion of each bottom plate 43 on its one side portion isdetachably coupled to the distal end of a cylinder shaft 44a projectingfrom the front surface of the housing 22.

Each cylinder 44 provided in the housing 22 constitutes the secondopening/closing drive unit while the cylinder 34 that opens/closes thepool hopper 25, constitutes the first opening/closing drive unit and acylinder 60 opens/closes a lower-stage timing hopper 50 which will bedescribed later. Inversely to the cylinders 34 and 60, the cylinder 44moves the corresponding bottom plate 43 forward to open the lower opensurface of the cylindrical body 36 of the corresponding metering hopper35, and moves the corresponding bottom plate 43 backward to close thelower open surface of the cylindrical body 36 of the correspondingmetering hopper 35.

Each hopper support 40 is detachably coupled to a disk-like couplingplate 45 arranged on the front surface of the housing 22 through alocking mechanism 46.

Each coupling plate 45 is supported by a load cell 47 fixed in thehousing. Each cylinder 44 is also fixed to the coupling plate 45, andits cylinder shaft 44a projects ahead of the housing 22 through thecoupling plate 45.

Accordingly, the weights of the metering hopper 35, the hopper support40, the guide shafts 42, the bottom plate 43, the cylinder 44, thecoupling plate 45, and the locking mechanism 46 are constantly appliedto each load cell 47, and the weight of the target metering object isadded to this constant load.

The timing hoppers 50 are arranged below the corresponding meteringhoppers 35.

Each timing hopper 50 is constituted by a cylindrical body 51 and abottom plate 59, in completely the same manner as the pool hopper 25.The cylindrical body 51 of the timing hopper 50 is supported on thefront surface of the housing 22 to be aligned in the reverse directionwith respect to the cylindrical body 36 of the metering hopper 35 (thefront and rear sides of the timing hoppers 50 are aligned with those ofthe pool hoppers 25) at a position where its upper open surface 51aopposes to overlap the lower open surface 36b of the cylindrical body 36of the metering hopper 35, such that it can receive the target meteringobject discharged from the cylindrical body 36 of the metering hopper35.

More specifically, as shown in FIG. 4, among flanges 51c and 51d at thefront and rear portions of the lower end of the cylindrical body 51 ofeach timing hopper 50, the flange 51c where two locking holes 52 areformed faces the front. In this state, the locking holes 52 are lockedby locking pins 56 provided to project upright on a pin fixing plate 54at the inner edge of a front plate 53a of each of frames 53 fixed to theright and left portions of the front surface 22b of the housing 22.Hence, the cylindrical body 51 of the timing hopper 50 is placed on abottom plate 59, which is supported on a pair of guide shafts 58provided between the front plate 53a of the frame 53 and the frontsurface of the housing to extend parallel to each other, and is slidback and forth.

Each bottom plate 59 is formed into a rectangle having a size enough toclose the lower open surface of the timing hopper 50, and its rearportion on its one side portion is detachably coupled to the distal endof a cylinder shaft 60a projecting from the front surface of the housing22.

Each cylinder 60 in the housing 22 constitutes the third opening/closingdrive unit. Similarly to the cylinder 34 that opens/closes the poolhopper 25, the cylinder 60 retracts the corresponding cylinder shaft 60ato move the corresponding bottom plate 59 backward, thereby opening thelower open surface 51b of the cylindrical body 51 of the correspondingtiming hopper 50. The cylinder also pushes the corresponding cylindershaft 60a forward to move the corresponding bottom plate 59 forward,thereby closing the lower open surface 51b of the cylindrical body 51 ofthe corresponding timing hopper 50.

Two conveyors 65 and 66 are arranged left and right below the pluralityof (ten in this embodiment) timing hoppers 50.

The left conveyor 65 receives the target metering objects dischargedfrom the five left timing hoppers and conveys them to its right end.

The right conveyor 66 receives the target metering objects dischargedfrom the five right timing hoppers and conveys them to its left end.

The two conveyors 65 and 66 are supported by the front surface 22b ofthe housing 22 and are respectively driven by motors 68 in the housing22.

A funnel-shaped collecting chute 70 is supported under a portion betweenthe two conveyors 65 and 66.

As shown in FIG. 6, the collecting chute 70 has, at its upper portion, asquare open surface 71 of a necessary minimal size for receiving thetarget metering object conveyed from the ends of the conveyors 65 and66, and a discharge port 72 at its lower portion. The collecting chute70 has a sharply tilted inner wall surface so that the target meteringobject having tackiness, which is received through the open surface 71,can be discharged through the discharge port 72.

The collecting chute 70 is supported by a pair of support members 73provided to extend from the front surface 22b of the housing 22 forwardparallel to each other, such that it can be withdrawn forward.

Elongated plate-shaped return regulating plates 75 and 76 are arranged,between the left edge of the open surface 71 of the collecting chute 70and the lower surface of the right end of the conveyor 65 and betweenthe right edge of the open surface 71 and the lower surface of the leftend of the conveyor 66, respectively, to extend in the widthwisedirection of the conveyors.

The return regulating plates 75 and 76 have a shape of a thin rectangleand have a length almost equal to the width of the belts of theconveyors 65 and 66. Lower edge portions 75b and 76b of the returnregulating plates 75 and 76 are respectively fixed by a pair of rotatingshafts 80 and 81 projecting forward from the front surface of thehousing 22 to be parallel to each other, while upper edge portions 75aand 76a of the return regulating plates 75 and 76 come close (almost incontact with) to the belts of the conveyors 65 and 66 on the lowersurface side.

The rotating shafts 80 and 81 are driven by motors 82 and 83 provided inthe housing 22, to pivot the return regulating plates 75 and 76 througha predetermined angle toward the inner side of the collecting chute 70,and to return them to the initial positions.

The motors 82 and 83 are driven by a control unit (to be describedlater) when the target metering objects on the conveyors 65 and 66 aredischarged from their end portions on the collecting chute 70 side, topivot the return regulating plates 75 and 76.

The vibrating units 23, the cylinders 34, 44 and 60, the motors 68, andthe motors 82 and 83 described above are controlled by the control unitshown in FIG. 7.

More specifically, a combination selecting means 90 detects the weightsof the target metering objects supplied to the respective meteringhoppers from the output signals of the respective load cells 47. Whenthe sum of the weights is close or equal to the preset target weight,the combination selecting means 90 selects this combination of thetarget metering objects as the target combination. The combinationselecting means 90 outputs, to a metering hopper opening/closing means91, a combination signal for specifying metering hoppers that store thetarget metering objects selected to constitute this combination.

The metering hopper opening/closing means 91 drives the cylinders 44corresponding to the metering hoppers 35 specified by the combinationsignal almost simultaneously to move the bottom plates 43 forward, sothat the lower open surfaces of the cylindrical bodies 36 of themetering hoppers 35 are opened forward from the rear side, therebydischarging the target metering objects stored in the metering hoppers35 downward at once. Also, the metering hopper opening/closing means 91outputs, to a pool hopper opening/closing means 92 and a timing hopperopening/closing means 94, a metering hopper discharge signal forspecifying metering hoppers that are emptied of the target meteringobjects upon discharge (i.e., timing hoppers that have received thetarget metering objects from the metering hoppers).

When the lower open surfaces of the cylindrical bodies 36 are openedcompletely and the target metering objects in the cylindrical bodies 36are discharged completely, the bottom plates 43 are returned backwardfrom the front side to close the lower open surfaces of the cylindricalbodies 36.

When the metering hopper opening/closing means 91 receives a meteringhopper opening/closing permission signal from the timing hopperopening/closing means 94 (to be described later), except for the startof the operation, it opens and closes metering hoppers storing targetmetering objects that constitute a next combination selected by thecombination selecting means 90.

After the lower open surfaces of the cylindrical bodies 36 of themetering hoppers 35 specified by the metering hopper discharge signalare opened completely and the target metering objects in the meteringhoppers 35 are discharged, when the bottom plates 43 of the cylindricalbodies 36 of the metering hoppers 35 are started to return backward, thepool hopper opening/closing means 92 drives the cylinders 34 of the poolhoppers 25 corresponding to these metering hoppers almost simultaneouslyto start retraction of the bottom plates 33, and opens the lower opensurfaces of the cylindrical bodies 36 of these pool hoppers 25 backwardfrom the front side, thereby discharging the target metering objectsstored in the cylindrical bodies 26 of the pool hoppers 25 downward.

After the lower open surfaces of the cylindrical bodies 26 are openedcompletely and the target metering objects in the cylindrical bodies 26are discharged completely, the pool hopper opening/closing means 92pushes the bottom plates 33 forward to close the lower open surfaces ofthe cylindrical bodies 26 forward from the rear side.

When the opening/closing operation of the bottom plate 33 is completed,the pool hopper opening/closing means 92 outputs, to a feeder drivemeans 93, a pool hopper discharge signal specifying pool hoppers thatare emptied by this discharge.

The feeder drive means 93 drives the vibrating units 24 corresponding tothe pool hoppers specified by the pool hopper discharge signal for apredetermined period of time, to supply target metering objects to theemptied pool hoppers 25.

The timing hopper opening/closing means 94 temporarily stores themetering hopper discharge signal sent from the metering hopperopening/closing means 91, starts a conveyor drive circuit 102 to drivethe conveyors 65 and 66 for almost half the revolution at apredetermined speed V, and sequentially specifies, among the pluralityof timing hoppers 50, the timing hoppers 50, ranging from those at thetwo ends farthest from the collecting chute 70 to those on the innerside that are closest to the collecting chute 70, at a time intervalcorresponding to the convey speed of the conveyors 65 and 66.

When the target metering object is stored in the specified timinghopper, the timing hopper opening/closing means 94 drives the cylinder60 corresponding to this timing hopper 50 to retract its bottom plate59, and opens the lower open surface of its cylindrical body 51 backwardfrom the front side, thereby discharging the target metering objectstored in the cylindrical body 51 onto the conveyor 65 or 66. After thelower open surface of this cylindrical body 51 is opened completely andthe target metering object in the cylindrical body 51 is dischargedcompletely, the timing hopper opening/closing means 94 pushes the bottomplate 59 forward to close the lower open surface of the cylindrical body51 forward from the rear side.

By this opening/closing control operation of the timing hoppers 50, thetarget metering objects stored in the timing hoppers 50 are conveyed tothe collecting chute 70 as they are gathered on the same positions ofthe conveyors 65 and 66.

The timing hopper opening/closing means 94 outputs the metering hopperopening/closing permission signal to the metering hopper opening/closingmeans 91 when the bottom plate 59 of a timing hopper closest to thecollecting chute 70 is started to close.

The operation of this combined metering apparatus will be described withreference to FIGS. 8A to 8D, FIGS. 9A to 9G, and FIGS. 10A and 10B.

FIGS. 8A to 8D show the convey operation of the target metering objects(indicated by hatched portions) by the metering hoppers 35, the timinghoppers 50, and the conveyors 65 and 66.

FIGS. 9A to 9G show, from the side surface side, the operation of thebottom plates with respect to the respective cylindrical bodies of theset of pool hopper 25, the metering hopper 35, and the timing hopper 50that are arranged vertically.

Assume that target metering objects have been supplied to all the conveytroughs 24, the pool hoppers 25, and the metering hoppers 35 in advance,and that the weights of the target metering objects supplied to themetering hoppers 35 have been detected.

Among combinations of the weights, a combination which is close to orequal to the preset target weight is selected by the combinationselecting means 90.

For example, if the target metering objects stored in the second, fifth,ninth, and tenth metering hoppers, when counted from the left, areselected to constitute the combination, the cylinders 44 correspondingto these metering hoppers are driven by the metering hopperopening/closing means 91, and the target metering objects selected toconstitute the combination are discharged at once into the correspondingtiming hoppers 50, as shown in FIG. 8A.

More specifically, from a state wherein the target metering objects arestored in the pool hopper 25 and the metering hopper 35, as shown inFIG. 9A, the bottom plate 43 of the metering hopper 35 is pushed forward(to the right in FIG. 9A) to open the lower open surface 36b of thecylindrical body 36 forward from the rear side (from the left in FIG.9A), and the target metering object falls to be stored in thelower-stage timing hopper 50, the upper open surface 51a of whichcoincides with the lower open surface 36b of the cylindrical body 36.

As shown in FIG. 9B, when the bottom plate 43 of the metering hopper 35is moved to a position to open the lower open surface 36b of thecylindrical body 36 completely, the target metering object stored in thecylindrical body 36 is discharged completely, and is stored in thelower-stage timing hopper 50.

When the target metering objects selected to constitute the combinationare stored in the timing hoppers 50 from the respective metering hoppers35 in this manner, as shown in FIG. 8B, the target metering objects aresupplied to the second, fifth, ninth, and tenth emptied metering hoppers35, when counted from the left, from the corresponding pool hoppers 25.

This supply operation is started simultaneously when the bottom plate 43of the metering hopper 35 is started to return.

More specifically, as shown in FIG. 9B, when the lower open surface 36bof the cylindrical body 36 of the metering hopper 35 is openedcompletely and the target metering object is discharged completely, asshown in FIG. 9C, the bottom plate 43 is retracted to close the loweropen surface 36b of the cylindrical body 36 backward from the frontside. Almost in synchronism with the return movement of the bottom plate43, the bottom plate 33 of the upper-stage pool hopper 25 is retractedto open the lower open surface 26b of the cylindrical body 26 backwardfrom the front side.

Therefore, the first part of the target metering object in thecylindrical body 26 of the pool hopper 25, which falls through the gapbetween the front end of the bottom plate 33 and the front end of thelower open surface 26b of the cylindrical body 26 falls along the frontend-side inner wall of the cylindrical body 36 of the lower-stagemetering hopper 35. Thus, this target metering object is placed on thebottom plate 43 that closes the lower open surface 36b of thecylindrical body 36 from the front side, and will not fall through thegap between the lower open surface 36b of the cylindrical body 36 andthe rear end of the bottom plate 43.

As shown in FIG. 9D, when the bottom plate 43 of the metering hopper 35is moved to a position to completely close the lower open surface 36b ofthe cylindrical body 36, the bottom plate 33 of the upper-stage poolhopper 25 is also moved to a position to completely open the lower opensurface 26b of the cylindrical body 26, so that the target meteringobject in the cylindrical body 26 is discharged completely.

Then, after the bottom plate 33 of the pool hopper 25 is driven forwardto close the lower open surface 26b of the cylindrical body 26, thevibrating unit 23 is driven, so that the target metering object is newlysupplied from the convey trough 24 to the emptied pool hopper 35, asshown in FIG. 9E.

While the target metering objects are supplied from the pool hoppers 25to the emptied metering hoppers 35 and the target metering objects aresupplied from the convey troughs 24 to the emptied pool hoppers 25 inthis manner, the conveyors 65 and 66 are driven, the timing hoppers aresequentially specified starting from the one farthest from thecollecting chute 70, and the target metering objects in the specifiedtiming hoppers are discharged onto the conveyors 65 and 66.

More specifically, of the timing hoppers 50 at the two ends that arespecified first, the timing hopper 50 at the right end (tenth from theleft) storing the target metering object is opened and closed, and thetarget metering object in it is discharged onto the conveyor 66, asshown in FIG. 8B. When this target metering object is conveyed to justbelow the ninth timing hopper 50 counted from the left, the second andninth timing hoppers 50 counted from the left are specified, and thetarget metering objects stored in these timing hoppers 50 arerespectively discharged onto the conveyors 65 and 66, as shown in FIG.8C.

Therefore, the target metering object discharged from the ninth timinghopper 50 counted from the left is conveyed toward the collecting chute70 as it is stacked on the target metering object discharged from thetenth timing hopper 50 counted from the left and conveyed by theconveyor 66.

When the target metering objects on the conveyors 65 and 66 are conveyeduntil the fifth and sixth timing hoppers 50 counted from the left, whichare the closest to the collecting chute 70, are opened and closed, thesetwo timing hoppers 50 are specified, and the fifth timing hopper 50 fromthe left is opened and closed.

Therefore, the target metering object discharged from the fifth timinghopper 50 counted from the left is conveyed toward the collecting chute70 as it is stacked on the target metering object discharged from thesecond timing hopper 50 counted from the left and conveyed by theconveyor 65.

A next combination is selected by the combination selecting means 90while the target metering objects are discharged from the respectivetiming hoppers 50 and are conveyed by the conveyors 65 and 66 as well.

Assume that the target metering object in the fourth metering hopper 35counted from the left, which is the closest to the collecting chute 70,is selected again to constitute the combination. As shown in FIG. 9F,after the bottom plate 59 of the timing hopper 50 closest to thecollecting chute 70 is opened and the target metering object in thecylindrical body 51 (the target metering object selected by the previouscombination selection) is discharged completely, as shown in FIG. 9G,the bottom plate 59 is started to return forward. Almost in synchronismwith this 77 return, the bottom plate 43 of the upper-stage meteringhopper 35 is started to move forward, thereby discharging the targetmetering object in the cylindrical body 35.

In this case, in the same manner as in the supply operation from thepool hopper 25 to the metering hopper 35 described above, the first partof the target metering object in the cylindrical body 36 of the poolhopper 35, which falls through the gap between the rear end of thebottom plate 43 and the rear end of the lower open surface 36b of thecylindrical body 36 falls along the rear end-side inner wall of thecylindrical body 51 of the lower-stage timing hopper 50. Thus, thistarget metering object is placed on the bottom plate 59 that closes thelower open surface 51b of the cylindrical body 51 from the rear side,and will not fall through the gap between the lower open surface 51b ofthe cylindrical body 51 and the front end of the bottom plate 59.

When the bottom plate 59 of the timing hopper 50 is moved to a positionto completely close the lower open surface 51b of the cylindrical body51, the bottom plate 43 of the metering hopper 35 is moved to a positionto completely open the lower open surface 36b of the cylindrical body36. After the target metering object in the cylindrical body 36 isdischarged completely, when the bottom plate 43 is started to returnbackward, as shown in FIG. 9C, the bottom plate 33 of the upper-stagepool hopper 25 is started to open, thereby starting supply of the nexttarget metering object.

Most of the target metering objects that are gathered on the conveyors65 and 66 and conveyed to the collecting chute 70 are unloaded from theends of the conveyors 65 and 66 to fall into the collecting chute 70.Meanwhile, same of the target metering objects stick to the beltsurfaces of the conveyors 65 and 66 due to their tackiness and go roundto the lower surfaces, as shown in FIG. 10A.

However, as the upper edge portions 75a and 76a of the return regulatingplate 75 and 76 are located at positions where they are almost incontact with the belts on the lower surfaces of the conveyors, thetarget metering objects that have gone round to the lower surfaces ofthe belts are scraped from the belts to fall into the collecting chute70.

When the drive of the conveyors 65 and 66 by a half revolution iscompleted, as shown in FIG. 10B, the motors 82 and 83 are driven almostsimultaneously to rotate the return regulating plates 75 and 76 througha predetermined angle toward the inner side of the collecting chute 70,thereby returning them to the initial position. Then, the targetmetering objects attaching to the return regulating plates 75 and 76also fall into the collecting chute 70.

Therefore, the target metering objects selected to constitute thecombination do not remain on the conveyors 65 and 66 or fall outside thecollecting chute 70, but are entirely discharged into the collectingchute 70 and are discharged through the discharge port 72.

Thereafter, of the target metering objects supplied from theuppermost-stage pool hoppers 25 to the middle-stage metering hoppers 35,those selected to constitute the combination based on their weights aredischarged to the lowermost-stage timing hoppers 50, and are dischargedfrom the respective timing hoppers 50 into the conveyors 65 and 66, inthe same manner as described above.

In this manner, in the combined metering apparatus of this embodiment,the direction in which the lower open surface of the cylindrical body ofthe upper-stage hopper is opened and the direction in which the loweropen surface of the cylindrical body of the lower-stage hopper is closedare set the same, and the operation of closing the lower-stage hopperand the operation of opening the upper-stage hopper are performed almostsimultaneously. Therefore, the convey efficiency of the target meteringobject from the upper-stage hopper to the lower-stage hopper can beincreased remarkably.

In this embodiment, three vertical stages of hoppers are constituted bythe pool hoppers 25, the metering hoppers 35, and the timing hoppers 50.The target metering objects are conveyed from the uppermost-stage poolhoppers 25 to the middle-stage metering hoppers 35 and weighed. Thetarget metering objects selected to constitute the combination areconveyed from the metering hoppers to the lowermost-stage timing hoppers50 and are discharged onto the conveyors. However, the present inventioncan similarly be applied to a combined metering apparatus which isconstituted by two stages of pool hoppers and metering hoppers withouttiming hoppers, or by four or more stages of hoppers.

In the above embodiment, the bottom plates of the respective hoppers aremoved in a direction perpendicular to the direction along which thehoppers of the respective stages are aligned (in a directionperpendicular to the front surface of the housing 22). However, thebottom plates of the respective hoppers may be moved in a directionalong which the hoppers of the respective stages are aligned (to beparallel to the front surface of the housing 22).

In the above embodiment, with regard to the pool hoppers and themetering hoppers that are arranged vertically, assuming that the forwarddirection (a direction to separate from the front surface of thehousing) is defined as the first direction and that the backwarddirection (a direction to be close to the front surface of the housing)is defined as the second direction, when the bottom plates of themetering hoppers are moved in the second direction, the bottom plates ofthe pool hoppers are also moved in the second direction almost insynchronism with the movement of the bottom plates of the meteringhoppers. However, the backward direction (a direction to be close to thefront surface of the housing) may be defined as the first direction, andthe forward direction (a direction to separate from the front surface ofthe housing) may be defined as the second direction, just like therelationship between the metering hoppers and the timing hoppers.

As described above, in the combined metering apparatus according to thefirst embodiment of the present invention, with regard to the hoppersthat are vertically adjacent to each other, the direction in which thelower open surface of the cylindrical body of the upper-stage hopper isopened and the direction in which the lower open surface of thecylindrical body of the lower-stage hopper is closed are set the same.Also, when the bottom plate of the lower-stage hopper is moved in adirection to close the lower open surface of the correspondingcylindrical body, the bottom plate of the upper-stage hopper is moved inthe same direction in almost synchronism with the movement of the bottomplate of the lower-stage plate, thereby opening the lower open surfaceof the cylindrical body of the upper-stage hopper. Therefore, the conveyefficiency of the target metering object from the upper-stage hopper tothe lower-stage hopper can be increased remarkably, thereby improvingthe operational efficiency of the entire apparatus.

Therefore, according to the first embodiment as described above, thecombined metering apparatus having an improved operational efficiencycan be provided by increasing the convey efficiency of the targetmetering object from the upper-stage hopper to the lower-stage hopper.

The second embodiment of the present invention will be described withreference to the accompanying drawings.

FIG. 11 is a front view of only the main part of FIGS. 1A and 1B as thesecond embodiment of the present invention, FIG. 12 is a plan view ofthe same, and FIG. 14 is a perspective view of the same.

A channel-like mount plate 308 is mounted inside a base body 301 servingas part of the housing 22 shown in FIGS. 1A and 1B.

A mount side 302a of a load cell 302 is fixed to a projecting portion308a of the mount plate 308.

The depth and length of the mount plate 308 are set such that a loadside 302b of the load cell 302 corresponding to the load cell 47 shownin FIG. 5 projects slightly from the front surface of the base body 1.

For this purpose, the base body 1 is punched circularly, and the loadside 302b of the load cell 302 projects to the front surface side.

A disk-like panel 309 having a diameter slightly smaller than that ofthe circle punched in the base body 301 is mounted on the projectingload side 302b of the load cell 302.

A channel-like support member 310 is fixed to the front surface of thepanel 309.

Upwardly open notches 310a are formed in the upper ends of the two sidesof the support member 10.

An air cylinder 305 is mounted inside the panel 309, and its piston 311is moved reciprocally on the front surface of the panel 309.

More specifically, the mount side 302a of the load cell 302 is fixed tothe base body 301, and the support member 310, to which a load isapplied, and the air cylinder 305 are mounted on the load side 302b ofthe load cell 302 through the panel 309.

A decoration panel 312 is mounted to surround the circular punched holeof the base body 301, and a bellows 313 made of rubber is provided toclose the gap between the decoration panel 312 and the panel 309.

A hanging member 314 has the shape of a channel, and a round rod 314a isprovided to extend between the two opposing sides of the hanging member314.

A square rod-shaped fixing block 315 is mounted on the one side of thehanging member 314.

Two guide pins 316 are mounted on the upper surface of the fixing block315.

Round rod-shaped guide rails 317 are fixed on a surface of the fixingblock 315 opposing the hanging member 314 at portions close to the twoend faces of the fixing block 315 in the cantilevered manner.

An opening/closing member 304 has the shape of a substantially squareflat plate, and is placed on the two guide rails 317.

Regarding the shape of the opening/closing member 4, its one side whichis placed on one guide rail 317 has the shape of a flat plate, and asemicircular groove 304a is formed in the lower surface of its otherside which is placed on the other guide rail 317 to match the shape ofthe guide rail 317.

Hence, the opening/closing member 304 can slide on the guide rails 317.

Part of the side surface of the opening/closing member 304 where thesemicircular groove 304a is formed extends, and a notched portion 304bis formed in this extension so as to lock a lock nut 318 mounted on thedistal end of the piston 311 of the air cylinder 305.

A semicircular groove 304c is formed in the lower surface of theopening/closing member 304 to be engageable with the piston 311.

A cylindrical member 303 corresponding to the metering hopper 35 of thefirst embodiment has a substantially square outer shape, and its upperopening portion is wider than its lower opening portion. A flange 319 isformed on one outer side of this lower opening portion, and two guideholes 320 are formed in the flange 319.

By utilizing the guide holes 320, the cylindrical member 303 is placedon the fixing block 315 such that its guide holes 320 are fitted withthe guide pins 316 provided to the fixing block 315. Accordingly, thebottom surface of the cylindrical member 303 is brought into contactwith the upper surface of the opening/closing member 304.

Regarding supply/discharge of air used for driving the air cylinder 305,first, an air supply unit (not shown) and the base body 301 areconnected through an air supply pipe 321.

A flexible tube 306 (e.g., a spiral tube made of a resin is preferable)is connected between the air supply pipe 321 fixed to the base body 301and a solenoid valve 322 fixed to the air cylinder 305.

The intermediate portion of the tube 306 is fixed and held with a fixingplate 323 fixed to the air cylinder 305.

Rigid or flexible pipes 324 are connected between the solenoid valve 322and a supply port 305a of the air cylinder 305, between a supply port305b of the air cylinder 305 and the solenoid valve 322, and between thesolenoid valve 322 and an exhaust unit 307, respectively.

The exhaust unit 307 is fixed to the fixing plate 323 mounted to the aircylinder 305 such that its exhaust direction is set in the horizontaldirection.

The operation will be described.

First, the round rod 314a of the hanging member 314 is engaged with thenotches of the support member 310, and the guide rails 317 are mountedto extend from the fixing block 315.

Subsequently, the opening/closing member 304 is placed on the two guiderails 317 such that the notched portion 304b of the opening/closingmember 304 is engaged with the lock nut 318 of the piston 311 of the aircylinder 305.

The cylindrical member 303 is placed on the opening/closing member 304and the fixing block 315 such that the guide holes 320 are fitted on theguide pins 316 on the fixing block 315.

At this time, since air is sent from the air supply pipe 321 to thesolenoid valve 322 and is supplied to the supply port 305a side of theair cylinder 305, the piston 311 of the air cylinder 305 is retracted.

More specifically, the lower open surface of the cylindrical member 303is closed with the opening/closing member 304 so that a target meteringobject W can be introduced into the cylindrical member 303 and metered.

The target metering object W is introduced into the cylindrical member303 and stacked on the upper surface of the opening/closing member 304.

In this state, the load of the metering container formed by thecylindrical member 303 and the opening/closing member 304 and that ofthe deposited target metering object W are metered by the load cell 302mounted to the mount plate 308, together with the loads of the guiderails 317, the fixing block 315, the hanging member 314, the supportmember 310, and the panel 309.

The weights of the air cylinder 305 mounted to the panel 309, thesolenoid valve 322 accompanying the air cylinder 305, and the fixingplate 323 of the tube 306 are also metered as the load of the load cell302, as a matter of course.

Since air is constantly supplied from the air supply pipe 321, apressure acts in the interior of the tube 306 connected between the-basebody 301 and the load side of the load cell 302.

However, as the tube 306 is flexible, it does not have rigidity, so thatthis pressure does not act on the load side of the load cell 302.

When metering of the target metering object W is ended, the targetmetering object is discharged from the cylindrical member 303.

In this case, the solenoid valve 322 is switched to supply air to thesupply port 305b of the air cylinder 305.

Then, the piston 311 is pushed out, and the opening/closing member 304is moved on the guide rails 317 accordingly, as indicated by an arrow Ain FIG. 11. Hence, the lower open surface of the cylindrical member 303is opened, as shown in FIG. 13, to drop and discharge the targetmetering object W.

At this time, air pushed out from the supply port 305a side of the aircylinder 305 passes through the pipes 324 and the solenoid valve 322 andis exhausted from the exhaust unit 307.

Since the exhaust unit 307 is mounted on the fixing plate 323 to be setin the horizontal direction, the air injecting direction is alsohorizontal.

Therefore, the air injecting direction and the load direction of theload cell 302 are perpendicular to each other, so that the influence ofair injection does not act on the load.

When discharge of the target metering object W is ended, the solenoidvalve 322 is switched, and air is supplied from the supply port 305aside of the air cylinder 305 to the air cylinder 305.

The piston 311 is retracted into the air cylinder 305 to move theopening/closing member 304 to a position to close the lower open surfaceof the cylindrical member 303, as indicated by an arrow B in FIG. 13,and the target metering object W is introduced.

At this time, air pushed out from the supply port 305b of the aircylinder 305 passes through the pipes 324 and the solenoid valve 322 andis exhausted from the exhaust unit 307.

After this, the operations of introduction, metering, and discharge ofthe target metering object W are repeated sequentially in accordancewith the movement of the opening/closing member 304. Every time meteringis performed, an electric signal output from the strain sensor 302c ofthe load cell 302 is supplied to an operational circuit (not shown) tocalculate the weight of the target metering object W.

Since the mount side of the load cell is fixed to the base body and thecylindrical member, the opening/closing member, and the air cylinder aremounted on the load side of the load cell, as described above, therewill be no unstable contact portions during metering, so that stablemetering can be performed. Also, since no special mechanism is requiredfor preventing contact, the structure is simple.

In addition, since the operating direction of the air cylinder and theexhaust direction of air from the exhaust unit are different from theload direction of the load cell, the load of the load cell will notvary.

Since the tube for supplying air from the base body side to the aircylinder is flexible, even if an air pressure is applied to the tube,the tube between the base body and the air cylinder does not becomerigid, thereby not adversely affecting the load of the load cell.

Therefore, according to the second embodiment as described above, acombined metering apparatus having high measuring precision with asimple structure can be provided.

The third embodiment will be described. Since the arrangement andoperation of the third embodiment are identical to those of the firstembodiment shown in FIGS. 1A, 1B, 2, 3, 6, 7, 8A to 8D, and 10, adescription thereof will be omitted, and only portions different fromthe first embodiment will be described with reference to FIGS. 15 to 22.

Both FIGS. 15 and 16 show the arrangement of a timing hopper 50 to bedescribed later.

First, as shown in FIG. 15, in a cylindrical body 26, in addition toflanges identical to those of the first embodiment, a tilted surface 26eis formed on the lower surface of the other flange 26d such that itsheight from its lower end surface is gradually increased toward theouter side.

A bottom plate 33 is supported on each of a pair of guide shafts 32 suchthat the height of its upper surface 33a is the same as the height of apin fixing plate 29.

The upper surface 33a of each bottom plate 33 is formed flat into asubstantially square shape having a size enough to close a lower opensurface 26b of the cylindrical body 26. A notched portion 134 having apredetermined width is formed in the rear side of one side portion (leftside when seen from the front surface) of the bottom plate 33 such thatit is notched inwardly.

A first bearing portion 135 having the shape of a U-shaped groove withan open side is formed in the side surface between the notched portion134 and the rear end portion of the bottom plate 33.

As shown in FIG. 16, a second bearing portion 136 having the shape of aU-shaped groove with a lower open side is formed in the notched portion134 side end portion of the lower surface 33b of the bottom plate 33 toextend by a predetermined length from the rear end of the lower surface.

The first bearing portion 135 and the second bearing portion 136 areadjacent to be parallel to each other.

Cylinders 34 serving as drive units for moving the bottom plates 33 ofrespective pool hoppers 25 are provided in a housing 22 at positions tocorrespond to the respective pairs of guide shafts 32.

A drive shaft 34a of each cylinder 34 projects from the front surface ofthe housing 22, and is reciprocally driven at a position slightlyoutside one (the left one when seen from the front) of the pair of guideshafts 32 to be parallel to the guide shafts 32.

The gap between the drive shaft 34a of each cylinder 34 and one (theleft one) guide shaft 32 is set almost equal to the gap between thefirst bearing portion 135 and the second bearing portion 136 of thebottom plate 33.

A distal end portion 34b of the drive shaft 34a has such a length thatit can laterally enter the notched portion 134 of the bottom plate 33and an outer diameter larger than the inner diameter of the firstbearing portion 135.

Each bottom plate 33 is slidably supported on the pair of guide shafts32 while the distal end portion 34b of the drive shaft 34a is receivedby the notched portion 134, the drive shaft 34a is loosely fitted in thefirst bearing portion 135, the left guide shaft 32 is engaged with thesecond bearing portion 136, and the other (right) guide shaft 32 isabutted against the other end portion of a lower surface 33b.

Accordingly, as shown in FIG. 17, when the right end of the bottom plate33 is lifted upward and the bottom plate 33 is pivoted counterclockwiseabout the drive shaft 34a engaging with the first bearing portion 135 asthe fulcrum, the second bearing portion 136 and the left guide shaft 32are disengaged from each other.

After this disengagement, when the bottom plate 33 is lifted in theupper right direction, the drive shaft 34a and the first bearing portion135 are also disengaged from each other, so that the bottom plate 33 canbe removed easily.

Reversely, when mounting the bottom plate 33, after the left end of thebottom plate 33 is directed downward and the first bearing portion 135is engaged with the drive shaft 34a, the right end of the bottom platemay be moved downward clockwise, and the second bearing portion 136 andthe left guide shaft 32 may be engaged with each other.

The cylindrical body 26 of each pool hopper 25 is supported on thebottom plate 33 such that the lower surface of its front-side flange 26cis abutted against the upper surface of the pin fixing plates 29 byinserting a pair of locking pins 31 of the pin fixing plates 29 inlocking holes 27 and that the lower end face of its rear-side flange 26dis abutted against the upper surface 33a of the bottom plate 33.

Thus, when the bottom plate 33 of the cylindrical body 26 is driven bythe cylinder 37 to move to a position where the front end of the bottomplate 33 and the pin fixing plates 29 are brought into contact with eachother, the lower open surface 26b of the cylindrical body 26 is closedcompletely. When the front end of the bottom plate 33 is moved to thelower end face of the rear-side flange 26d, the lower open surface 26bis opened completely.

Since the cylindrical body 26 is restricted merely in its horizontalmovement by the locking pins 31 that are inserted in the locking holes27 from below, when it is only lifted upward to disengage the lockingpins 31 and the locking holes 27 from each other, it can be removedeasily.

Metering hoppers 35 are arranged in an array below the pool hoppers 25.

As shown in FIG. 18, each metering hopper 35 is constituted by acylindrical body 36 having completely the same shape as that of thecylindrical body 26 of the pool hopper 25, and a bottom plate 43 havingcompletely the same shape as that of the bottom plate 33 of the poolhopper 25.

The cylindrical body 36 is supported to be aligned in the reversedirection with the cylindrical body 26 of the pool hopper 25 such thatits upper open surface 36a vertically overlaps the lower open surface26b of the cylindrical body 26 of the upper-stage pool hopper 25.

Two locking pins 41 provided to project upright on the upper surface ofeach hopper support 40 supported by a front surface 22b of the housing22 are inserted through two locking holes 37 formed in one flange 36c,of flanges 36c and 36d provided to the front and rear sides of a loweropen surface 36b of the cylindrical body 36.

A pair of guide shafts 42 are mounted to the two end portions of eachhopper support 40 so as to extend forward horizontally and to beparallel to each other at a gap identical to that of the pair of guideshafts 32 that support the bottom plate 33 of the pool hopper 25.

A bottom plate 43 is supported on the pair of guide shafts 42 to beguided by them to be slidable back and forth.

In completely the same manner as the bottom plate 33 of the pool hopper25, the upper surface 43 of each bottom plate 43 is formed flat into asubstantially square shape having a size enough to close the lower opensurface 36b of the cylindrical body 36. A notched portion 149 is formedon the rear side of one side portion (left side) of the bottom plate 43.

A first bearing portion 150 having the shape of a U-shaped groove withan open side is formed in the side surface between the notched portion149 and the rear end portion of the bottom plate 43.

As shown in FIG. 19, a second bearing portion 151 having the shape of aU-shaped groove with a lower open side is formed in the notched portion149 side end portion of a lower surface 48b of the bottom plate 43.

Cylinders 44 serving as drive units to move the bottom plates 43 of therespective pool hoppers 35 are provided in the housing 22 at positionsto correspond to the respective pairs of guide shafts 42.

A drive shaft 44a of each cylinder 44 projects from the front surface ofthe housing 22, and is reciprocally driven at a position slightlyoutside one (the left one when seen from the front) of the pair of guideshafts 42 to be parallel to the guide shafts 42.

The gap between the drive shaft 44a of each cylinder 44 and one (theleft one) guide shaft 42 is set almost equal to the gap between thefirst bearing portion 150 and the second bearing portion 151 of thebottom plate 43.

A distal end portion 44b of the drive shaft 44a has such a length thatit can laterally enter the notched portion 149 of the bottom plate 43and an outer diameter larger than the inner diameter of the firstbearing portion 150.

Each bottom plate 43 is slidably supported on the pair of guide shafts42 while the distal end portion 44b of the drive shaft 44a is receivedby the notched portion 149, the drive shaft 44a is loosely fitted in thefirst bearing portion 150, the left guide shaft 42 is engaged with thesecond bearing portion 151, and the other (right) guide shaft 42 isabutted against the other end portion of the lower surface 43b.

Accordingly, the bottom plate 43 of each metering hopper 35 can also beeasily removed and mounted by a simple pivot operation, as shown in FIG.17.

The cylindrical body 36 of each metering hopper 35 is supported on thebottom plate 43 such that the lower surface of its rear-side flange 36cis abutted against the upper surface of the hopper support 40 byinserting the pair of locking pins 41 of the hopper support 40 in thelocking holes 37 and that the lower end face of its front-side flange36d having the tilted surface 36e is abutted against an upper surface48a of the bottom plate 43.

Thus, when the bottom plate 43 of the cylindrical body 36 is driven bythe cylinder 44 to move to a position where the rear end of the bottomplate 43 and the hopper support 40 are brought into contact with eachother, the lower open surface 36b of the cylindrical body 36 is closedcompletely. When the front end of the bottom plate 43 is moved to thelower end face of the front-side flange 36d, the lower open surface 36bis opened completely.

The timing hoppers 50 are arranged below the respective metering hoppers36.

As shown in FIGS. 15 and 16, each timing hopper 35 is constituted by acylindrical body 51 having completely the same shape as that of thecylindrical body 26 of the pool hopper 25, and a bottom plate 59 havingcompletely the same shape as that of the bottom plate 33 of the poolhopper 25.

The cylindrical body 51 is supported to be aligned in the reversedirection with the cylindrical body 36 of the metering hopper 35 (thatis, to be aligned with the cylindrical body 26 of the pool hopper 25 inthe same direction) such that its upper open surface 51a verticallyoverlaps the lower open surface 36b of the cylindrical body 36 of theupper-stage metering hopper 35.

Two locking holes 52 formed in one flange 51c, of flanges 51c and 51dprovided to the front and rear sides of a lower open surface 51b of thecylindrical body 51, are locked by locking pins 56 which are provided toproject upright on a pin fixing plate 54 on the inner edge of a frontplate 53a of each of frames 53 that are fixed to the right and leftportions of the front surface 22b of the housing 22.

A pair of guide shafts 58 are provided between the front plate 53a ofeach frame and the front surface of the housing 22 so as to extendforward horizontally and to be parallel to each other at a gap identicalto that of the pair of guide shafts 32 that support the bottom plate 33of the pool hopper 25.

A bottom plate 59 is supported on the pair of guide shafts 58 to beguided by them to be slidable back and forth.

In completely the same manner as the bottom plates 33 and 43 of the poolhoppers 25 and the metering hoppers 35, an upper surface 59a of eachbottom plate 59 is formed flat into a substantially square shape of asize to close a lower open surface 61b of a cylindrical body 61. Anotched portion 70 is formed in the rear side of one side portion (leftside) of the bottom plate 59.

A first bearing portion 71 having the shape of a U-shaped groove with anopen side is formed in the side surface between the notched portion 70and the rear end portion of the bottom plate 59.

A second bearing portion 72 having the shape of a U-shaped groove with alower open side is formed in the notched portion 70 side end portion ofa lower surface 59b of the bottom plate 59.

Cylinders 60 serving as drive units to move the bottom plates 59 thatsupport the respective timing hoppers 50 are provided in the housing 22at positions to correspond to the respective pairs of guide shafts 58.

A drive shaft 60a of each cylinder 60 projects from the front surface ofthe housing 22, and is reciprocally driven at a position slightlyoutside one (the left one when seen from the front) of the pair of guideshafts 58 to be parallel to the guide shafts 58.

The gap between the drive shaft 60a of each cylinder 60 and one (theleft one) guide shaft 58 is set almost equal to the gap between thefirst bearing portion 71 and the second bearing portion 72 of the bottomplate 59.

A distal end portion 60b of the drive shaft 60a has such a length thatit can laterally enter the notched portion 70 of the bottom plate 59 andan outer diameter larger than the inner diameter of the first bearingportion 71.

Each bottom plate 59 is slidably supported on the pair of guide shafts58 while the distal end portion 60b of the drive shaft 60a is receivedby the notched portion 70, the drive shaft 60a is loosely fitted in thefirst bearing portion 71, the left guide shaft 58 is engaged with thesecond bearing portion 72, and the other (right) guide shaft 58 isabutted against the other end portion of the lower surface 59b.

Accordingly, the bottom plate 59 of each timing hopper 50 can also beeasily removed and mounted by a simple pivot operation, as shown in FIG.17.

The cylindrical body 51 of each timing hopper 50 is supported on thebottom plate 69 such that the lower surface of its front-side flange 51cis abutted against the upper surface of the pin fixing plate 54 byinserting the pair of locking pins 56 of the pin fixing plate 54 in thelocking holes 52 and that the lower end face of its rear-side flange 51dhaving the tilted surface 51e is abutted against the upper surface 59aof the bottom plate 59.

Thus, when the bottom plate 59 of the cylindrical body 51 is driven bythe cylinder 60 to move to a position where the front end of the bottomplate 59 and the hopper support 40 are brought into contact with eachother, the lower open surface 51b is closed completely. When the frontend of the bottom plate 59 is moved to the lower end face of therear-side flange 51d, the lower open surface 51b is opened completely.

FIG. 20 shows the positions of the cylindrical bodies 26, 36, and 51 ofthe pool hopper 25, the metering hopper 35, and the timing hopper 50,that are vertically arranged in three stages, from the side surface.

The cylindrical body 36 of the metering hopper 35 is supported, within arange in which its upper open surface 36a vertically overlaps the loweropen surface 26b of the cylindrical body 26 of the pool hopper 25, at aposition close to a side (namely, the front surface side of the housing22) toward which the bottom plate 33 is moved when the pool hopper 25 isopened.

The cylindrical body 51 of the timing hopper 50 is supported, within arange in which its upper open surface 51a vertically overlaps the loweropen surface 36b of the cylindrical body 36 of the metering hopper 35,at a position close to a side (in a direction to remote from the frontsurface of the housing) toward which the bottom plate 43 is moved whenthe metering hopper 35 is opened.

The operation of the combined metering apparatus according to the thirdembodiment will be described. The basic operation of the thirdembodiment is similar to that of the first embodiment shown in FIGS. 8Ato 8D, and thus description will be made with reference to FIGS. 21A to21G.

FIGS. 21A to 21G show, from the side surface side, the operation of thebottom plates with respect to the respective cylindrical bodies of theset of pool hopper 25, the metering hopper 35, and the timing hopper 50that are arranged vertically.

From a state wherein the target metering objects are stored in the poolhopper 25 and the metering hopper 35, as shown in FIG. 21A, the bottomplate 43 of the metering hopper 35 is pushed forward (to the right inFIG. 21A) to open the lower open surface 36b of the cylindrical body 36forward from the rear side (from the left in FIG. 21A), and the targetmetering object falls to be stored in the lower-stage timing hopper 50.

As shown in FIG. 21B, when the bottom plate 43 of the metering hopper 35is moved to a position to open the lower open surface 36b of thecylindrical body 36 completely, the target metering object stored in thecylindrical body 36 is discharged completely, and is stored in thelower-stage timing hopper 50.

Subsequently, as shown in FIG. 21B, when the lower open surface 36b ofthe cylindrical body 36 of the metering hopper 35 is opened completelyand the target metering object is discharged completely, as shown inFIG. 21C, the bottom plate 43 is retracted to close the lower opensurface 36b of the cylindrical body 36 backward from the front side.Almost in synchronism with the return movement of the bottom plate 43,the bottom plate 33 of the upper-stage pool hopper 25 is retracted toopen the lower open surface 26b of the cylindrical body 26 backward fromthe front side.

Therefore, the first part of the target metering object in thecylindrical body 26 of the pool hopper 25, which falls through the gapbetween the front end of the bottom plate 33 and the front end of thelower open surface 26b of the cylindrical body 26 falls along the frontend-side inner wall of the cylindrical body 36 of the lower-stagemetering hopper 35. As the bottom plate 43 that supports the meteringhopper 35 is moved in the same direction as the moving direction of thebottom plate 33 and the upper open surface 36a of the cylindrical body36 of the metering hopper 35 is set close to the side toward which thebottom plate 33 is moved, the target metering object is placed on thebottom plate 43 that closes the lower open surface 36b of thecylindrical body 36 from the front side, and will not fall through thegap between the lower open surface 36b of the cylindrical body 36 andthe rear end of the bottom plate 43.

As shown in FIG. 21D, when the bottom plate 43 supporting the meteringhopper 35 is moved to a position to completely close the lower opensurface 36b of the cylindrical body 36, the bottom plate 33 of theupper-stage pool hopper 25 is also moved to a position to completelyopen the lower open surface 26b of the cylindrical body 26, so that thetarget metering object in the cylindrical body 26 is dischargedcompletely.

At this time, the target metering object which is discharged finallyfrom the pool hopper 25 is slightly dragged in the direction in whichthe bottom plate 33 is moved and is obliquely discharged to the housing22 side. As described above, the upper open surface 36a of thecylindrical body 36 of the lower-stage metering hopper 35 is located ata position close to the housing side with respect to the lower opensurface 26b of the cylindrical body 26 of the pool hopper 25. Thus, thetarget metering object being discharged from the pool hopper 25 will notbe scattered to outside the metering hopper 35 but reliably falls intothe cylindrical body 36 of the metering hopper 35.

Since the two ends of the lower surface of the bottom plate 43 thatsupports the metering hopper 35 are supported by the pair of guideshafts 42, the load of the target metering object that falls from abovedoes not directly act on the drive shaft 44a. Also, only one of the pairof guide shafts 42 is engaged with the second bearing portion 151 andthe bottom plate 43 is in contact with the other guide shaft 42 fromabove. Thus, even if the pair of guide shafts have a low parallelism,the bottom plate 43 is moved smoothly.

Since the first bearing portion 150 engaged with the drive shaft 44a andthe second bearing portion 151 engaged with the guide shaft 42 are closeto each other, the rotation moment applied by the drive shaft 44a to thebottom plate 43 is very small, and this rotation moment will notinterfere with the movement of the bottom plate 43.

Even if vertical vibration is applied to the bottom plate 43, thevertical movement of the guide shaft 42 is regulated by the drive shaft44a laterally engaged with the bottom plate 43, so that the bottom plate43 will not be disengaged.

The above discussion similarly applies to the bottom plate 33 of thepool hopper 25 and the bottom plate 59 that supports the timing hopper50.

When supply of the target metering object to the metering hopper 35 iscompleted in this manner, after the bottom plate 33 of the pool hopper25 is driven forward to close the lower open surface 26b of thecylindrical body 26, the vibrating unit 23 is driven, so that the targetmetering object is newly supplied from a convey trough 24 to the emptiedpool hopper 25, as shown in FIG. 21E.

While the target metering objects are supplied from the pool hoppers 25to the emptied metering hoppers 35 and the target metering objects aresupplied from the convey troughs 24 to the emptied pool hoppers 25 inthis manner, conveyors 65 and 66 are driven, the timing hoppers aresequentially specified starting from one farthest from a collectingchute 70, and the target metering objects in the specified timinghoppers are discharged onto the conveyors 65 and 66.

A next combination is selected by a combination selecting means 90 whilethe target metering objects are discharged from the respective timinghoppers 50 and are conveyed by the conveyors 65 and 66 as well.

Assume that the target metering object in the fourth metering hopper 35counted from the left, which is the closest to the collecting chute 70,is selected again to constitute the combination. As shown in FIG. 21F,after the bottom plate 59 of the timing hopper 50 closest to thecollecting chute 70 is opened and the target metering object in thecylindrical body 51 (the target metering object selected by the previouscombination selection) is discharged completely, as shown in switch 21G,the bottom plate 59 is started to return forward. Almost in synchronismwith this return, the bottom plate 43 of the upper-stage metering hopper35 is started to move forward, thereby discharging the target meteringobject in the cylindrical body 35.

This operation is performed in the same manner as in the supplyoperation from the pool hopper 25 to the metering hopper 35 describedabove.

When the bottom plate 59 supporting the timing hopper 50 is moved to aposition to completely close the lower open surface 51b of thecylindrical body 51, the bottom plate 43 of the metering hopper 35 ismoved to a position to completely open the lower open surface 36b of thecylindrical body 36.

At this time, the target metering object which is discharged finallyfrom the metering hopper 35 is slightly dragged in the direction inwhich the bottom plate 43 is moved and is obliquely discharged forward(in a direction to separate from the housing 22).

The upper open surface 51a of the cylindrical body 51 of the lower-stagetiming hopper 50 is located at a position close to the front side withrespect to the lower open surface 36b of the cylindrical body 36 of themetering hopper 35. The target metering object being discharged from themetering hopper 40 will not be scattered outside the timing hopper 50but reliably falls into the cylindrical body 51 of the timing hopper 50.

After the target metering object in the cylindrical body 36 isdischarged completely in this manner, when the bottom plate 43 isstarted to return backward, the bottom plate 33 of the upper-stage poolhopper 25 is started to open, as shown in FIG. 21C, and supply of thenext target metering object is started.

When cleaning each hopper, its cylindrical body can be removed easilyonly by lifting it upward and disengaging the locking pins from thelocking holes.

While the cylindrical body is removed, when one end portion (right endwhen seen from the front) of the bottom plate is lifted upward todisengage the second bearing portion from the left guide shaft, and thenthe bottom plate is lifted in the upper right direction, each bottomplate can be removed only by disengaging the first bearing portion fromthe drive shaft.

Since the cylindrical bodies and bottom plates of the respective hoppersare of the same shape, a large number of cylindrical bodies and bottomplates that are removed can be cleaned without being discriminatedaccording to the types of hoppers, and the cleaned cylindrical bodiesand bottom plates can be used for arbitrary hoppers. Thus, very highconvenience can be obtained in the cleaning operation and componentmaintenance.

In this combined metering apparatus, in order to convey the targetmetering object from the upper-stage hopper to the lower-stage hopperefficiently, the direction in which the lower open surface of thecylindrical body of the upper-stage hopper is opened and the directionin which the lower open surface of the cylindrical body of thelower-stage hopper is closed are set the same, and the operation ofclosing the lower-stage hopper and the operation of opening theupper-stage hopper are performed almost simultaneously.

Instead of this, the timing at which the opening operation of the bottomplate of the upper-stage hopper is started and the timing at which theclosing operation of the bottom plate of the lower-stage hopper isstarted may be synchronized completely, since the upper open surface ofthe lower-stage hopper is set close to a side toward which the loweropen surface of the upper-stage hopper is opened.

Alternatively, the timing at which the opening operation of the bottomplate of the upper-stage hopper is started may be set slightly ahead ofthe timing at which the closing operation of the bottom plate of thelower-stage hopper is started.

Namely, in either case, the target metering object discharged from theupper-stage hopper can be reliably stored in the lower-stage hopper. Thearrangement in which the position of the lower-stage hopper is deviatedfrom the upper-stage hopper, as described above, largely contributes toan improvement in convey efficiency of the target metering object.

The tilted surface 26e and tilted surfaces 36e and 61e, which are tiltedto be higher on the outer sides, are respectively formed on the lowersurfaces of the flanges 26d, 36d, and 51d of the cylindrical bodies 26,36, and 51 of the hoppers 25, 35, and 50 on the sides toward which thebottom plates 33, 43, and 69 that support the cylindrical bodies 26, 36,and 51 are opened.

Hence, as shown in FIG. 22A, tailings D of the target metering objectwhich have moved to the outer side of the cylindrical body 26 (36, 51)while they attach onto the bottom plate 33 (43, 59) are not scraped bythe side wall of the flange 26d (36d, 51d) when the bottom plate 33 (43,59) is returned in the closing direction, but are directly moved to thelower open surface side of the cylindrical body 26 (36, 51).

Therefore, an article which is dried and denatured will not mix in thetarget metering object in the lower-stage hopper or will not cause anerror in the metering result.

In the above embodiment, in order to improve the discharge efficiency ofthe target metering object, the direction in which the lower opensurface of the cylindrical body of the upper-stage hopper is opened andthe direction in which the lower open surface of the cylindrical body ofthe lower-stage hopper is closed are set the same. Also, when the bottomplate of the lower-stage hopper is moved in a direction to close thelower open surface of the corresponding cylindrical body, the bottomplate of the upper-stage hopper is moved in the same direction in almostsynchronism with the movement of the bottom plate of the lower-stageplate, thereby opening the lower open surface of the cylindrical body ofthe upper-stage hopper.

This arrangement does not limit the present invention. The presentinvention can also be similarly applied to a combined metering apparatusin which the direction in which the lower open surface of thecylindrical body of the upper-stage hopper is opened and the directionin which the lower open surface of the cylindrical body of thelower-stage hopper is opened are the same.

As described above, in the combined metering apparatus according to thethird embodiment of the present invention, the lower-stage hopper isarranged, within a range in which the lower open surface of theupper-stage hopper and the upper open surface of the lower-stage hopperoverlap vertically, to be close to the side toward which the bottomplate of the upper-stage hopper is opened. Thus, the target meteringobject which is discharged obliquely downward along with the movement ofthe bottom plate of the upper-stage hopper can be reliably received inthe upper open surface of the cylindrical body of the lower-stagehopper, so that convey of the target metering object can be performedreliably.

In the combined metering apparatus according to the third embodiment ofthe present invention, the two end portions of the bottom plate aresupported by a pair of guide shafts that are substantially parallel toeach other, and the bottom plate is engaged with the drive shaft of thedrive unit, so that the bottom plate is slidably moved in the lengthwisedirection of the guide shafts. Therefore, the load of the targetmetering object supplied onto the bottom plate from above is notdirectly applied to the drive shaft, and the bottom plate can be movedsmoothly, thereby reliably conveying the target metering object.

In the combined metering apparatus according to the third embodiment ofthe present invention, a tilted surface, the height of which from thelower end face is gradually increased farther to the side, is formed onthe outer circumferential portion of the lower end of the cylindricalbody constituting the hopper. The cylindrical body is arranged such thatthis tilted surface is located on a side toward which the bottom plateis moved to open the lower open surface of the cylindrical body.Therefore, the tailings of the target metering object which have movedto the outer side of the cylindrical body while they attach onto thebottom plate are stacked on the outer wall of the cylindrical body andare not discharged into the lower-stage hopper, thereby stablyperforming convey of the target metering object.

The fourth embodiment of the present invention will be described withreference to the accompanying drawings.

FIG. 23 is a front view of only the main part of FIGS. 1A and 1B as thefourth embodiment of the present invention, and FIG. 24 is a plan viewof the same.

Similar to the second embodiment described above, the fourth embodimentis related to a load cell 2 portion corresponding to the load cell 47 ofthe first embodiment shown in FIG. 5.

In the fourth embodiment, a description of portions identical to thoseof FIGS. 11, 12, and 14 that are employed in the second embodimentdescribed above is omitted, and only portions that are different fromthe second embodiment will be described with reference to FIGS. 23 to25.

Referring to FIGS. 23 and 24, regarding supply and discharge of airemployed for driving an air cylinder 305, a rigid pipe 321 is connectedbetween an air supply unit (not shown) and a solenoid valve 322 fixed tothe outer side of a base body 301, and flexible tubes 306 and 307 areconnected between the solenoid valve 322 and the air cylinder 305 withtheir intermediate portions being fixed and held by a fixing plate 323mounted on the air cylinder 305.

Two tubes 356 and 357 respectively serve to supply and discharge airupon switching operation of the solenoid valve 322. For example, theflexible tubes 356 and 357 are preferably spiral tubes made of a resin.

As shown in the drawings, the tubes 356 and 357 extend almost in thehorizontal direction entirely between the base body 301 and the fixingplate 323, although they sag slightly, to connect the solenoid valve 322and the air cylinder 305 with each other.

The discharge air is discharged from the solenoid valve 322 provided tothe outside of the base body to the outer side of the base body 301through an exhaust unit 300.

As the exhaust unit 300 is not connected to the load cell 302, thedischarge air does not adversely affect the load cell 302. Hence, thedischarge air need not have a directivity.

As a matter of course, the solenoid valve 322 may be mounted on theinner side of the base body 301 instead. It suffices if the exhaust unit300 is directed to the outer side of the base body 301.

The operation will be described.

A hanging member 314 hangs from a support member 310 as a round rod 314aof the hanging member 314 is engaged with the notches of the supportmember 310 and guide rails 317 extend from a fixing block 315 fixed tothe hanging member 314.

Subsequently, an opening/closing member 304 is placed on the two guiderails 317 such that a notched portion 304b of the opening/closing member304 is engaged with a lock nut 318 of a piston 311 of the air cylinder305.

The cylindrical member 303 is placed on the opening/closing member 304and the fixing block 315 such that its guide holes 320 are fitted onpins 316 on the fixing block 315.

At this time, air is sent from the air supply pipe 321 to the solenoidvalve 322 and is supplied to the supply port 5a side of the air cylinder305 through the tube 356.

Hence, the piston 311 of the air cylinder 305 is set in the retractedstate.

More specifically, the lower open surface of the cylindrical member 303is closed with the opening/closing member 304 so that a target meteringobject W can be introduced into the cylindrical member 303 and metered.The target metering object W is introduced into the cylindrical member303 and stacked on the upper surface of the opening/closing member 304.

In this state, the load of the metering container formed by thecylindrical member 3 and the opening/closing member 304 and that of thedeposited target metering object W are metered by the load cell 302fixed to a mount plate 308, together with the loads of the guide rails317, the fixing block 315, the hanging member 314, the support member310, and the panel 309.

The weight of the air cylinder 305 mounted to the panel 309 and that ofthe fixing plate 323 of the tubes 356 and 357 accompanying the aircylinder 305 are also metered as the load of the load cell 302, as amatter of course.

Air is constantly supplied from the air supply pipe 321, and a pressureacts in the interior of the tube 356 connected between the solenoidvalve 322 and the air cylinder 305.

However, as the tube 356 is flexible, it does not have rigidity, so thispressure does not act on the load side of the load cell 302.

When metering of the target metering object W is ended, the targetmetering object is discharged from the cylindrical member 303. In thiscase, the solenoid valve 322 is switched to supply air to the supplyport 305b of the air cylinder 305 through the tube 357.

Then, the piston 311 is pushed out, and the opening/closing member 304is moved on the guide rails 317 accordingly, as indicated by an arrow Ain FIG. 23. Hence, the lower open surface of the cylindrical member 303is opened, as shown in FIG. 25, to drop and discharge the targetmetering object W.

At this time, air blown out from the supply port 305a side of the aircylinder 305 passes through the tube 356 and the solenoid valve 322 andis discharged from the exhaust unit 300 to the outside of the base body1.

When discharge of the target metering object W is ended, the solenoidvalve 322 is switched, and air is supplied from the supply port 305aside of the air cylinder 305 to the air cylinder 305 through the tube 6.

The piston 311 is retracted into the air cylinder 305 to move theopening/closing member 304 to a position to close the lower open surfaceof the cylindrical member 303, as indicated by an arrow B in FIG. 25,and the target metering object W is introduced.

At this time, air blown out from the supply port 305b of the aircylinder 305 passes through the tube 357 and the solenoid valve 322 andis discharged from the exhaust unit 300 to the outside of the base body301.

After this, the operations of introduction, metering, and discharge ofthe target metering object W are repeated sequentially in accordancewith the movement of the opening/closing member 304 driven by the aircylinder 305. Every time metering is performed, an electric signaloutput from a strain sensor 302c of the load cell 302 is calculated byan operational circuit (not shown), thereby calculating the weight ofthe target metering object W.

As described above, according to the fourth embodiment, since the mountside of the load cell is fixed to the base body, and the cylindricalmember, the opening/closing member, and the air cylinder are mounted tothe load side of the load cell, there will be no unstable contactportions during metering, so that stable metering can be performed.Also, since no special mechanism is required for preventing contact, thestructure is simple.

In addition, in the fourth embodiment, since the operating direction ofthe air cylinder is different from the load direction of the load cell,the load of the load cell will not vary.

In the fourth embodiment, since the tubes for supplying air from thebase body side to the air cylinder and exhausting air from the aircylinder to the outside of the base body are flexible, even if an airpressure is kept applied to the tubes, the tubes between the base bodyand the air cylinder do not become rigid, thereby not adverselyaffecting the load of the load cell.

Moreover, in the fourth embodiment, since the air exhaust unit isprovided to be directed to the outside of the base body, a lubricantcontained in the air will not attach to the inner side of the base body,thereby preventing deposition of contamination and dust.

The fifth embodiment of the present invention will be described withreference to the accompanying drawings.

FIG. 26 shows the overall arrangement of a combined metering apparatus410 according to the fourth embodiment of the present invention.

In this combined metering apparatus 410, a plurality of linear feeders,intermediate hoppers, and metering hoppers are arranged annularly in thecircumferential direction of a prismatic housing. FIG. 26 shows onlypart of the plurality of linear feeders, the intermediate hoppers, andmetering hoppers that are arranged annularly.

Referring to FIG. 26, a base table 411 of the combined meteringapparatus 410 has a substantially square outer shape, and is supportedby legs 412 mounted on the four corners of its lower surface.

An inverted conical support hole 413 for supporting a collecting chute400 (to be described later) is formed in the center of the base table411, and four housing supports 414 are mounted on the inner wall surfaceof the support hole 413 to project upward.

A prismatic housing 415 having, e.g., 412 side surfaces is arrangedabove the support hole 413 such that its lower surface 415a side issupported by the housing supports 414.

A circular feeder 416 is arranged at the center of an upper surface 415bof the housing 415, and a plurality of (e.g., 12) linear feeders 420 arearranged radially around the circular feeder 416.

The circular feeder 416 is constituted by a circular umbrella-shapedconvey table 417 and a vibrating drive unit 418. The convey table 417supported on the upper end of a drive shaft 418a of the vibrating driveunit 418 is vertically vibrated while being rotated reciprocally,thereby dispersing, to its peripheral portion, the target meteringobject which is supplied by dropping by an article convey unit (e.g., aconveyor) (not shown) from above to the top portion of the convey table417.

The convey table 417 of the circular feeder 416 which is brought intocontact with the target metering object is monolithically formed intothe shape of a circular umbrella with a synthetic resin, e.g.,polypropylene incorporated with an anti-fungus material such as silverzeolite. As shown in FIG. 27, the hexagonal distal end of the driveshaft 418 is received in a bearing 417a provided at the center of thelower surface of the convey table 417, and a set screw 417b isthreadably engaged with the drive shaft 418 from the top portion side ofthe convey table 417, so that the convey table 417 is coupled to thedrive shaft 418a.

Hence, the convey table 417 can be removed from the vibrating drive unit418 by loosening the set screw 417b.

Each linear feeder 420 is constituted by a gutter-like convey table 421and a vibrating drive unit 422. The target metering object unloaded fromthe convey table 417 of the circular feeder 416 is received by theconvey table 421, and the convey table 421 is vibrated toward the outercircumference of the housing 415, thereby linearly conveying the targetmetering object to a position above the respective side surfaces of thehousing 415.

Similar to the convey table 417 of the circular feeder 416, the conveytable 421 of the linear feeders 420 which is brought into contact withthe target metering object is formed integrally with a synthetic resin,e.g., polypropylene incorporated with an anti-fungus material such assilver zeolite. As shown in FIG. 28, L-shaped hooks 421b and 421c areprovided at the front and rear portions of a lower surface 421a of theconvey table 421. The hook 421b is locked at the rear portion of avibrating table 422a of the vibrating drive unit 422, and the hook 421cis locked by a locking member (patching lock) 422b mounted to the frontportion of the vibrating table 422a, so that the convey table 421 isfixed on the vibrating drive unit 422.

Accordingly, when the locking member 422b is unlocked, the convey table421 can be easily removed from the vibrating drive unit 422.

In this manner, since the convey tables 417 and 421 of the circularfeeder 416 and the plurality of linear feeders 420 are formed integrallywith a synthetic resin, e.g., polypropylene incorporated with ananti-fungus material such as silver zeolite, they can be madelightweight when compared to convey tables made of stainless steel.Thus, power required for vibration drive can be small, and the vibratingdrive unit can be made small.

Even if scratches are formed on the surfaces of the convey tables,proliferation of bacteria can be prevented due to the action of theanti-fungus material. Thus, a sufficiently high cleaning effect can beobtained only with water washing.

As shown in FIG. 26, intermediate hoppers 425 are arranged above therespective side surface 415c of the housing 415 to respectively receivethe target metering objects unloaded from the convey tables 421 of therespective linear feeders 420 and discharge them.

As shown in FIGS. 29 and 30, each intermediate hopper 425 is a doubleswing hopper in which the lower open surface of a prismatic hopper body426 having upper and lower openings is opened/closed with two dischargegates 427 and 428. The hopper body 426 and the discharge gates 427 and428 which are brought into contact with the target metering objectdischarged from the linear feeder 420 are formed integrally with asynthetic resin, e.g., polypropylene incorporated with an anti-fungusmaterial such as silver zeolite.

The inner wall surface of the hopper body 426 is waved to prevent thetarget metering object having tackiness from being left.

Pivot shafts 429 are provided to project from the two sides of a frontsurface 426a and the two sides of 426b of the hopper body 426, the lowerportion of which is formed into an inverted triangle. The two dischargegates 427 and 428 are pivoted while their two side portions aresupported by the pivot shafts 429, thereby opening/closing the tiltedlower open surface of the hopper body 426.

The inner wall surfaces of the discharge gates 427 and 428 are alsowaved to prevent the target metering object having tackiness from beingleft.

Two rectangular locking segments 430 and 431 are provided upright atright and left portions of the central portion of the rear surface 426bof the hopper body 426 to oppose each other.

Locking pins 432 and 433 project outward from the upper and lowerportions of the distal end sides of the locking segments 430 and 431.

A mechanism support plate 435 is fixed between the two locking segments430 and 431.

The mechanism support plate 435 has a fixing portion 435a and supportportions 436b and 436c. The fixing portion 435a is fixed, between thelocking segments 430 and 431, to the rear surface 426b of the hopperbody 426 by screwing. The support portions 436b and 436c are formed onthe lower portion of the fixing portion 435a, to be higher than thefixing portion 435a so as not to interfere with the opening/closingoperation of the two discharge gates 427 and 428, and extend to the leftand right. Lever shafts 437 and 438 are provided to project on thedistal ends of the support portions 436b and 436c, respectively.

The lever shafts 437 and 438 respectively support the intermediateportions of V-shaped pivot levers 440 and 441 to be pivotal in symmetricdirections.

Rollers 442 and 443 are mounted to the lower ends of the two pivotlevers 440 and 441, respectively.

The lower ends of link plates 444 and 445 are pivotally coupled to theupper ends of the two pivot levers 440 and 441, respectively.

The upper ends of the link plates 444 and 445 are pivotally coupled tothe upper ends of the side portions of the discharge gates 427 and 428,respectively. The intermediate portions of the link plates 444 and 445are biased by a spring 448 in directions to be retracted by each other.

The sizes of the respective portions are set such that when thedischarge gates 427 and 428 are kept closed, the intermediate portionsof the link plates 444 and 445 are abutted against the locking segments430 and 431, and the link plates 444 and 445 and the upper portions ofthe pivot levers 440 and 441 are aligned on one line.

Therefore, for example, when the roller of one pivot lever is pushedupward, the upper portion of this pivot lever is moved outwardlydownward, so that the link plate coupled to this pivot lever is pulleddownward, thereby opening the discharge gate coupled to this link plate.

Since the mechanism support plate 435, the pivot levers 440 and 441supported by the mechanism support plate 435, and the link plates 444and 445 are not usually brought into contact with the target meteringobject, they can be formed with either a synthetic resin incorporatingan anti-fungus material or a metal. If these components are formed witha synthetic resin incorporating an anti-fungus material, the entireportion of the hopper excluding the spring 448 can be cleaned at once atroom temperature.

If these components are formed with a metal, the mechanism support plate435 may be removed from the hopper body 426, and the hopper body 426 andthe discharge gates 427 and 428 may be cleaned at room temperature.

The intermediate hopper 425 formed in this manner is detachably lockedon the upper portion of the side surface of the housing 415.

More specifically, as shown in FIG. 31, a channel-like locking plate 450is mounted to the upper portion of a side surface 415c of the housing415.

The size of the gap between opposing segments 451 and 452 of the lockingplate 450 is slightly larger than the gap between the outer sides of thelocking segments 430 and 431 of the intermediate hopper 425. Grooves 453and 454 for receiving the upper locking pins 432 of the locking segments430 and 431 are formed in the upper portions of the opposing segments451 and 452. Stepped portions 455 and 456 to be abutted against thelower locking pins 433 of the locking segments 430 and 431 are formed inthe lower portions of the opposing segments 451 and 452.

The intermediate hopper 425 is supported by the housing 415 such thatthe upper locking pins 432 of its locking segments 430 and 431 arefitted in the upper grooves 453 and 454 of the locking plate 450 andthat the lower locking pins 433 are abutted against the stepped portions455 and 456 of the locking plate 450.

A drive lever 457 pivoted by a drive unit (e.g., a motor or an aircylinder) in the housing 415 is mounted below the locking plate 450.

Upon the pivot operation of the drive lever 457, the pivot levers 440and 441 of the intermediate hopper 425 are driven selectively, so thatthe discharge gates 427 and 428 are opened/closed selectively.

A locking plate 458 for supporting a metering hopper 470 (to bedescribed later), and drive levers 465 and 466 for opening/closing themetering hopper 470 are provided to project below the drive lever 457.

The locking plate 458 projects from the side surface of the housing 415as it is coupled to a metering unit (not shown) fixed in the housing.Grooves 461 and 462 are formed in the upper portions of opposingsegments 459 and 460 of the locking plate 458, and stepped portions 463and 464 are formed in the lower portions of the opposing segments 459and 460 of the locking plate 458, in completely the same manner as inthe locking plate 450.

The target metering objects discharged from the respective intermediatehoppers 425 are stored in the metering hoppers 470 arranged below them,and are metered.

As shown in FIGS. 32 and 33, the metering hopper 470 has almost the samearrangement as that of the intermediate hopper 425, except that theinterior of its hopper body 471 is divided into left and right storingportions 473 and 474 with a partitioning segment 472 provided upright atthe center.

More specifically, the metering hopper 470 is a double swing hopper inwhich the lower open surfaces of the respective storing portions 473 and474 of the prismatic hopper body 471 having upper and lower openings areopened/closed with two discharge gates 475 and 476 independently of eachother. The hopper body 471 and the discharge gates 475 and 476 which arebrought into contact with the target metering object are formedintegrally with a synthetic resin, e.g., polypropylene incorporated withan anti-fungus material such as silver zeolite.

The inner wall surface of the hopper body 471 is waved to prevent thetarget metering object having tackiness from being left.

Pivot shafts 477 are provided to project from the two sides of a frontsurface 471a and the two sides of a rear surface 471b of the hopper body471, the lower portion of which is formed into an inverted triangle.

The two discharge gates 475 and 476 are pivoted while their two sideportions are supported by the pivot shafts 477, thereby opening/closingthe lower open surfaces of the storing portions 473 and 474.

The inner wall surfaces of the discharge gates 475 and 476 are alsowaved to prevent the target metering object having tackiness from beingleft.

Two rectangular locking segments 480 and 481 are suspended at right andleft portions of the central portion of the rear surface 471b of thehopper body 471 to oppose each other.

Locking pins 482 and 483 project outward from the upper and lowerportions of the distal end sides of the locking segments 480 and 481.

A mechanism support plate 485 is fixed between the two locking segments480 and 481.

The mechanism support plate 485 has a fixing portion 485a and supportportions 485b and 485c. The fixing portion 485a is fixed, between thelocking segments 480 and 481, to the rear surface 471b of the hopperbody 471 by screwing. The support portions 485b and 485c are formed onthe lower portion of the fixing portion 485a, to be higher than thefixing portion 485a so as not to interfere with the opening/closingoperation of the two discharge gates 475 and 476, and extend to the leftand right. Lever shafts 487 and 488 are provided to project on thedistal ends of the support portions 485b and 485c, respectively.

The lever shafts 487 and 489 respectively support the intermediateportions of V-shaped pivot levers 490 and 491 to be pivotal in symmetricdirections.

Rollers 492 and 493 are mounted to the lower ends of the two pivotlevers 490 and 491, respectively.

The lower ends of link plates 449 and 495 are pivotally coupled to theupper ends of the two pivot levers 490 and 491, respectively.

The upper ends of the link plates 494 and 495 are pivotally coupled tothe upper ends of the side portions of the discharge gates 475 and 476,respectively.

The intermediate portions of the link plates 494 and 495 are biased by aspring 498 in directions to be retracted by each other.

The metering hopper 470 is supported by the locking plate 458 by fittingthe upper locking pins 482 of the locking segments 480 and 481 in uppergrooves 461 and 462 of the locking plate 458 of the housing 415 andabutting the lower locking pins 483 against the stepped portions 463 and464 of the locking plate 458.

At this time, when the discharge gate 427 is opened, the target meteringobject in the intermediate hopper 425 is discharged into the storingportion 473 of the metering hopper 470.

The joint portion of the discharge gates 427 and 428 of the intermediatehopper 425 is located immediately above the partitioning segment 472 ofthe metering hopper 470 so that the target metering object in theintermediate hopper 425 is discharged into the storing portion 474 ofthe metering hopper 470 when the discharge gate 428 is opened.

The rollers 492 and 493 of the pivot levers 490 and 491 of the meteringhopper 470 are respectively located above the drive levers 465 and 466.

The weights of the target metering objects stored in the meteringhoppers 470 supported by the respective locking plates 458 are detectedby the metering units coupled to the locking plates 458 in units of thestoring portions, and the combination of the detected weights isselected.

When the drive lever, of the drive levers 465 and 466, which correspondsto the storing portion storing the target metering object selected toconstitute the combination is pivoted, the discharge gate correspondingto this storing portion is opened and then closed, and the targetmetering object selected to constitute the combination is discharged.

Similar to the intermediate hopper 425, since the mechanism supportplate 485, the pivot levers 490 and 491, and the link plates 494 and 495of the metering hopper 470 are not brought into direct contact with thetarget metering object, they can be formed with either a synthetic resinincorporating an anti-fungus material or a metal.

When cleaning the metering hopper, whether the entire hopper or only thehopper body and the gates will be cleaned at room temperature may beselected in accordance with the material of these components.

In this manner, since the hopper bodies 426 and 471, and the dischargegates 427, 428, 475, and 476 that are brought into contact with thetarget metering object in the intermediate hopper 425 and meteringhopper 470 are formed integrally with a synthetic resin, e.g.,polypropylene incorporating an anti-fungus material such as silverzeolite, they can be formed considerably lightweight when compared to ahopper made of stainless steel or a hopper having a gate. Thus, noiseoccurring when opening/closing the gate and load to the metering unitcan be small, and a small metering unit can be used.

Even if scratches are formed on the surfaces of these components,proliferation of bacteria can be prevented due to the operation of theanti-fungus material. Thus, a sufficiently high cleaning effect can beobtained only with cleaning at room temperature.

The target metering objects discharged from the respective meteringhoppers 470 are received by a collecting chute 500 mounted in thesupport hole 413 of the base table 411 and are discharged through adischarge port at the lower portion of the base table 411.

As shown in FIG. 34, the collecting chute 500 is formed into a funnelshape with four divided chute plates 501 such that it can be inserted inthe support hole 413 so as to escape from the housing supports 414provided upright in the support hole 413.

Each chute plate 501 is formed integrally with a synthetic resin, e.g.,polypropylene incorporating an anti-fungus material such as silverzeolite, in the same manner as the intermediate hoppers 425 and themetering hoppers 470.

Hence, the chute plates 501 become considerably lightweight compared tothe conventional chute plates made of stainless steel. Thus, the chuteplates that are very large as the components constituting the apparatuscan be removed or mounted easily. Also, similar to the convey path andthe hoppers, since proliferation of bacteria is prevented due to theoperation of the anti-fungus material, a sufficiently high cleaningeffect can be obtained with only cleaning at room temperature.

A discharge hopper 505 is detachably supported on the lower surface ofthe base table 411 with a discharge hopper support 503.

The target metering object discharged from the collecting chute 500 isstored in the discharge hopper 505 and is then discharged into apackaging machine (or a packaging line or the like).

As shown in FIG. 35, the discharge hopper 505 is a single swing hopperformed with a prismatic hopper body 506 and a discharge gate 507. Thehopper body 506 and the discharge gate 507 are formed integrally with asynthetic resin, e.g., polypropylene incorporating an anti-fungusmaterial such as silver zeolite. The inner wall surfaces of the hopperbody 506 and the discharge gate 507 are waved so that the targetmetering object having tackiness will not remain on them.

Although this discharge hoppers 505 is formed to be larger than theintermediate hopper 525 or the metering hoppers 570 in order to storethe target metering objects discharged from the plurality of meteringhoppers 570, since its hopper body 506 and discharge gate 507 are madeof a synthetic resin, it can be mounted and removed easily when comparedto the conventional hopper made of stainless steel. Also, as describedabove, the discharge hopper 505 can be cleaned easily due to theoperation of the anti-fungus material.

Locking segments 508 projecting outward are provided to the two sidesurfaces of the hopper body 506.

Locking holes 509 are formed in the locking segments 508.

The discharge hopper 505 is fixed at a position where it can receive thetarget metering object discharged from the collecting chute 500 in it,by inserting its two locking segments 508 in support grooves 503a of thedischarge hopper support 503 and locking its locking pins (not shown)biased to enter the support grooves 503a in the locking holes 509.

The locking pins can be unlocked by pulling out the discharge hopper 505firmly.

A pivot shaft 510 is provided to project through the front and rearsurfaces of the hopper body 506, and the side portion of the dischargegate 507 is pivotally supported by the pivot shaft 510 to open/close thelower open surface of the hopper body 106.

Shafts 511 and 512 are provided to project from the intermediate portionof the side portion of the discharge gate 507 and the front surface ofthe hopper body 506, respectively, and a spring 513 is hooked betweenthe shafts 511 and 512.

For this reason, the discharge gate 507 is constantly biased in adirection to close the lower open surface of the hopper body 506.

As shown in FIG. 26, the distal end portion of a drive arm 516 of anopening/closing drive unit 515 is locked by the shaft 512 of the pivotgate 510 side.

The opening/closing drive unit 515 fixed to the lower surface of thebase table 511 pivotally supports the other end of the drive arm 516with the edge portion of a rotary plate 517, and drives the rotary plate517 to rotate, so that the drive arm 516 is reciprocally moved almosthorizontally and the discharge gate 507 of the discharge hopper 505 isdriven to open/close, thereby discharging the target metering object inthe discharge hopper 505 to a packaging machine or a packaging line (notshown).

As described above, in this combined metering apparatus 410, the conveytables 417 and 421 of the circular feeder 416 and the linear feeders420, the hopper main bodies and discharge gates of the intermediatehoppers 425, the metering hoppers 470, and the discharge hopper 405, andthe collecting chute 500 are made of a synthetic resin incorporatinganti-fungus material. Thus, the entire apparatus can be madeconsiderably lightweight, its drive portion can be made small, andmachining aiming at preventing attachment of a target metering objecthaving tackiness can be performed at a low cost, thereby greatlydecreasing the cost of the entire apparatus.

Since the main bodies and discharge gates of the respective hoppers aremade of a synthetic resin, noise occurring upon an opening/closingoperation can be decreased. Even if scratches are formed on the surfacesof these components, proliferation of bacteria can be prevented due tothe action of the anti-fungus material, and a sufficiently highsterilization effect can be obtained with cleaning at room temperature,thereby greatly decreasing the cleaning cost.

In the fifth embodiment, the present invention is applied to thecombined metering apparatus in which a plurality of supply units andhoppers are annularly arranged along the outer circumference of aprismatic housing. The present invention can be applied not only to thecombined metering apparatus having this structure but also to a combinedmetering apparatus in which a plurality of supply units and hoppers arearranged in a line, as in the first embodiment shown in FIGS. 1A and 1B.

In the fifth embodiment, the hopper bodies and discharge gates of theintermediate hoppers, the metering hoppers, and the discharge hopper areformed with a synthetic resin incorporating an anti-fungus material.However, only the hopper bodies or the discharge gates may be formedwith a synthetic resin incorporating an anti-fungus material.

In the fifth embodiment, in the combined metering apparatus, all theconstituent components that are brought into contact with the targetmetering object, i.e., the convey tables of the supply units, the hopperbodies and gates of the respective hoppers, the collecting chute, andthe convey belts of the conveyors are formed with a synthetic resinincorporating an anti-fungus material. However, only some of thesecomponents may be formed with a synthetic resin incorporating ananti-fungus material.

In the fifth embodiment, the convey tables of the supply units, the mainbodies and discharge gates (bottom plates) of the hoppers, thecollecting chute, and the like are formed with polypropyleneincorporating silver zeolite as the anti-fungus material. However, otheranti-fungus materials, e.g., copper ion, quaternary ammonium salt, andthe like may be utilized. The synthetic resin material is not limited topolypropylene, and other materials can be used.

As described above, in the combined metering apparatus according to thefifth embodiment of the present invention, at least one component amonga plurality of supply units, hoppers, and the collecting units which arebrought into contact with the target metering object is formed with asynthetic resin incorporating an anti-fungus material. Thus, the entireapparatus can be made considerably lightweight, its drive portion can bemade small, and noise during driving can be decreased, thereby greatlydecreasing the cost.

Even if bacteria enter scratches formed on the surfaces of thesecomponents, proliferation of the bacteria is prevented due to the actionof the anti-fungus material, and a sufficiently high cleaning effect canbe obtained with cleaning at room temperature. Thus, the cleaning costis decreased greatly, satisfying requirements for both sanitation andcost.

We claim:
 1. A combined metering apparatus comprising:a supply forsupplying target metering objects; a plurality of pool hoppers forseparately receiving the target metering objects supplied by saidsupply, said plurality of pool hoppers being arranged in a horizontaldirection in sets, each pool hopper including a first cylindrical bodyhaving upper and lower open end portions, and a first bottom plateslidable to selectively open/close said lower open end portion of saidfirst cylindrical body; a plurality of metering hoppers for receivingthe target metering objects separately falling from said plurality ofpool hoppers, said plurality of metering hoppers being arranged in setson a lower stage side of said plurality of pool hoppers to correspondthereto, each of the metering hoppers including:(a) a second cylindricalbody having a receiving port at an upper portion thereof to receive thetarget metering object and a discharge port at a lower portion thereofto discharge the target metering object therethrough, and (b) a secondbottom plate slidable to selectively open/close said lower open endportion of said second cylindrical body; a plurality of metering devicesprovided in association with said plurality of metering hoppers toseparately meter the target metering objects received in said pluralityof metering hoppers and to output electric signals correspondingthereto, each of said metering devices including:(a) a base body havinga mount portion, (b) a load cell having:(i) a mount side mounted on themount portion of said base body, and (ii) a load side, (c) an engagemember mounted on the load side of said load cell and having a supportportion, with said second cylindrical body mounted on the supportportion of said engage member and said second bottom plate forming anopening/closing member movably attached relative to the discharge portof said second cylindrical body to open/close said discharge port ofsaid second cylindrical body, and (d) a drive portion mounted on saidengage member to drive said opening/closing member substantiallyhorizontally, wherein each of said metering devices permits stablemetering without preventing unstable contact portions during meteringsince the mount side of said load cell is substantially fixed to saidbase body and said second cylindrical body, said opening/closing member,and said drive portion are substantially mounted on the load side ofsaid load cell via said engage member; a selecting unit for selecting acombination of the target metering objects providing a predeterminedmetered value in said plurality of metering hoppers in accordance withthe electric signals from said plurality of metering devices; and adevice for collecting and discharging the target metering objectsfalling from corresponding ones of said plurality of metering hoppers inaccordance with the combination of the target metering objects selectedby said selecting unit.
 2. A combined metering apparatus according toclaim 1, wherein each of said plurality of metering devices includes,when said drive portion comprises an air cylinder,a flexible tubeconnected to supply air from said base body to said air cylinder, and anexhaust unit mounted to said load side of said load cell to direct airdischarged from said air cylinder almost horizontally.
 3. A combinedmetering apparatus according to claim 1, further comprising:a firstopening/closing drive unit related to said plurality of pool hoppers tomove said first bottom plate in a first direction to close said loweropen end portion of said first cylindrical body and to move said firstbottom plate in a second direction opposite to the first direction toopen said lower open end portion of said first cylindrical body, and asecond opening/closing drive unit forming said drive portion and relatedto said plurality of metering hoppers to move said second bottom platein the second direction to close said lower end portion of said secondcylindrical body and to move said second bottom plate in the firstdirection to open said lower end portion of said second cylindricalbody.
 4. A combined metering apparatus according to claim 3, furthercomprising a control unit for controlling said first and secondopening/closing drive units such that movement of said second bottomplate in the second direction and movement of said first bottom plate inthe second direction are almost in synchronism with each other.
 5. Acombined metering apparatus according to claim 1, whereinsaid upper openend portion of said second cylindrical body is larger than said upperopen end portion of said first cylindrical body, and said secondcylindrical body is arranged, within a range where said upper open endportion of said second cylindrical body and said lower open end portionof said first cylindrical body overlap vertically, close to a sidetoward which said first bottom plate is opened.
 6. A combined meteringapparatus according to claim 1, wherein each of said first and secondbottom plates has two end portions that are supported by a pair of guideshafts supported substantially horizontally and parallel to each other,and is slidably moved in a lengthwise direction of said pair of guideshafts upon reception of a force of a drive shaft of a drive unit.
 7. Acombined metering apparatus according to claim 6, wherein each of saidfirst and second bottom plates hasa first bearing portion formed into agroove in a side surface side of one end portion in order to laterallyreceive said drive shaft, thereby transmitting the force of said driveshaft to said bottom plate, a second bearing portion formed into agroove in a lower surface side of said one end portion in order toreceive one of said pair of guide shafts from below, thereby regulatingmovement of said bottom plate in a direction perpendicular to thelengthwise direction of said guide shafts, and each of said first andsecond bottom plates is supported by said pair of guide shafts such thatsaid drive shaft is engaged with said first bearing portion, one of saidpair of guide shafts is engaged with said second bearing portion, andthe other one of said guide shafts is abutted against a lower surface ofthe other end portion.
 8. A combined metering apparatus according toclaim 1, wherein each of said first and second cylindrical bodies has atilted surface at an outer circumferential portion of a lower endthereof, said tilted surface being formed such that a height thereoffrom a lower end face is gradually increased toward an outer side, andsaid tilted surface is located on a side toward which each of said firstand second bottom plates is moved to open said lower open end portion.9. A combined metering apparatus according to claim 1, wherein each ofsaid plurality of metering devices includes, when said drive portioncomprises an air cylinder,two flexible tubes connected between said basebody and said air cylinder to supply and discharge air, and an exhaustunit provided to discharge air discharged from said air cylinder to anoutside of said base body.
 10. A combined metering apparatus accordingto claim 9, further comprising:a first opening/closing drive unitrelated to said plurality of pool hoppers to move said first bottomplate in a first direction to close said lower open end portion of saidfirst cylindrical body and to move said first bottom plate in a seconddirection opposite to the first direction to open said lower open endportion of said first cylindrical body, and a second opening/closingdrive unit forming said drive portion and related to said plurality ofmetering hoppers to move said second bottom plate in the seconddirection to close said lower end portion of said second cylindricalbody and to move said second bottom plate in the first direction to opensaid lower end portion of said second cylindrical body.
 11. A combinedmetering apparatus according to claim 10, further comprising a controlunit for controlling said first and second opening/closing drive unitssuch that movement of said second bottom plate in the second directionand movement of said first bottom plate in the second direction arealmost in synchronism with each other.
 12. A combined metering apparatusaccording to claim 9, wherein:said upper open end portion of said secondcylindrical body is larger than said upper open end portion of saidfirst cylindrical body, and said second cylindrical body is arranged,within a range where said upper open end portion of said secondcylindrical body and said lower open end portion of said firstcylindrical body overlap vertically, close to a side toward which saidfirst bottom plate is opened.
 13. A combined metering apparatusaccording to claim 9, wherein each of said first and second bottomplates has two end portions that are supported by a pair of guide shaftssupported substantially horizontally and parallel to each other, and isslidably moved in a lengthwise direction of said pair of guide shaftsupon reception of a force of a drive shaft of a drive unit.
 14. Acombined metering apparatus according to claim 13, wherein each of saidfirst and second bottom plates hasa first bearing portion formed into agroove in a side surface side of one end portion in order to laterallyreceive said drive shaft, thereby transmitting the force of said driveshaft to said bottom plate, a second bearing portion, formed into agroove in a lower surface side of said one end portion in order toreceive one of said pair of guide shafts from below, thereby regulatingmovement of said bottom plate in a direction perpendicular to thelengthwise direction of said guide shafts, and each of said first andsecond bottom plates is supported by said pair of guide shafts such thatsaid drive shaft is engaged with said first bearing portion, one of saidpair of guide shafts is engaged with said second bearing portion, andthe other one of said guide shafts is abutted against a lower surface ofthe other end portion.
 15. A combined metering apparatus according toclaim 9, wherein each of said first and second cylindrical bodies has atilted surface at an outer circumferential portion of a lower endthereof, said tilted surface being formed such that a height thereoffrom a lower end face is gradually increased toward an outer side, andsaid tilted surface is located on a side toward which each of said firstand second bottom plates is moved to open said lower open end portion.16. A combined metering apparatus comprising:a supply for supplyingtarget metering objects; a plurality of pool hoppers for separatelyreceiving the target metering objects supplied by said supply, saidplurality of pool hoppers being arranged in a horizontal direction insets, each pool hopper including a first cylindrical body having upperand lower open end portions, and a first bottom plate slidable toselectively open/close said lower open end portion of said firstcylindrical body; a plurality of metering hoppers for receiving thetarget metering objects separately falling from said plurality of poolhoppers, said plurality of metering hoppers being arranged in sets on alower stage side of said plurality of pool hoppers to correspondthereto, each of the metering hoppers including a second cylindricalbody having upper and lower open end portions, and a second bottom plateslidable to selectively open/close said lower open end portion of saidsecond cylindrical body; a plurality of metering devices provided inassociation with said plurality of metering hoppers to separately meterthe target metering objects received in said plurality of meteringhoppers and to output electric signals corresponding thereto; aselecting unit for selecting a combination of the target meteringobjects providing a predetermined metered value in said plurality ofmetering hoppers in accordance with the electric signals from saidplurality of metering devices; a plurality of timing hoppers forreceiving the target metering objects falling from corresponding ones ofsaid plurality of metering hoppers in accordance with the combination ofthe target metering objects selected by said selecting unit, saidplurality of timing hoppers being arranged in sets on a lower stage sideof said plurality of metering hoppers to correspond thereto, each of thetiming hoppers including a third cylindrical body having upper and loweropen end portions, and a third bottom plate slidable to selectivelyopen/close said lower open end portion of said third cylindrical body ata timing delayed from opening/closing operations of other thirdcylindrical bodies by a predetermined period of time; and a device forcollecting and discharging the target metering objects falling from saidplurality of timing hoppers.
 17. A combined metering apparatus accordingto claim 16, wherein each of said plurality of metering devicesincludes:(a) a base body; (b) a load cell having a mount side mounted onsaid base body, with said second cylindrical body mounted on a load sideof said load cell and having a receiving port at the upper end portionthereof to receive the target metering object and a discharge port atthe lower end portion thereof to discharge the target metering objecttherethrough, and said second bottom plate forming an opening/closingmember mounted on said load side of said load cell to open/close saiddischarge port, (c) an air cylinder mounted on said load side of saidload cell to drive a piston in a horizontal direction to actuate saidopening/closing member, (d) a flexible tube connected to supply air fromsaid base body to said air cylinder; and (e) an exhaust unit mounted onsaid load side of said load cell to direct air discharged from said aircylinder almost horizontally.
 18. A combined metering apparatusaccording to claim 17, further comprising:first opening/closing driveunit related to said plurality of pool hoppers to move said first bottomplate in a first direction to close said lower open end portion of saidfirst cylindrical body and to move said first bottom plate in a seconddirection opposite to the first direction to open said lower open endportion of said first cylindrical body, and a second opening/closingdrive unit including said air cylinder and related to said plurality ofmetering hoppers to move said second bottom plate in the seconddirection to close said lower end portion of said second cylindricalbody and to move said second bottom plate in the first direction to opensaid lower end portion of said second cylindrical body.
 19. A combinedmetering apparatus according to claim 18, further comprising a controlunit for controlling said first and second opening/closing drive unitssuch that movement of said second bottom plate in the second directionand movement of said first bottom plate in the second direction arealmost in synchronism with each other.
 20. A combined metering apparatusaccording to claim 17, wherein:said upper open end portion of saidsecond cylindrical body is larger than said upper open end portion ofsaid first cylindrical body, and said second cylindrical body isarranged, within a range where said upper open end portion of saidsecond cylindrical body and said lower open end portion of said firstcylindrical body overlap vertically, close to a side toward which saidfirst bottom plate is opened.
 21. A combined metering apparatusaccording to claim 17, wherein each of said first and second bottomplates has two end portions that are supported by a pair of guide shaftssupported substantially horizontally and parallel to each other, and isslidably moved in a lengthwise direction of said pair of guide shaftsupon reception of a force of a drive shaft of a drive unit.
 22. Acombined metering apparatus according to claim 21, wherein each of saidfirst and second bottom plates hasa first bearing portion formed into agroove in a side surface side of one end portion in order to laterallyreceive said drive shaft, thereby transmitting the force of said driveshaft to said bottom plate, a second bearing portion formed into agroove in a lower surface side of said one end portion in order toreceive one of said pair of guide shafts from below, thereby regulatingmovement of said bottom plate in a direction perpendicular to thelengthwise direction of said guide shafts, and each of said first andsecond bottom plates is supported by said pair of guide shafts such thatsaid drive shaft is engaged with said first bearing portion, one of saidpair of guide shafts is engaged with said second bearing portion, andthe other one of said guide shafts is abutted against a lower surface ofthe other end portion.
 23. A combined metering apparatus according toclaim 17, wherein each of said first and second cylindrical bodies has atilted surface at an outer circumferential portion of a lower endthereof, said tilted surface being formed such that a height thereoffrom a lower end face is gradually increased toward an outer side, andsaid tilted surface is located on a side toward which each of said firstand second bottom plates is moved to open said lower open end portion.24. A combined metering apparatus according to claim 16, wherein each ofsaid plurality of metering devices includes:(a) a base body; (b) a loadcell having a mount side mounted on said base body, with said secondcylindrical body mounted on a load side of said load cell and having areceiving port at the upper end portion thereof to receive the targetmetering object and a discharge port at the lower end portion thereof todischarge the target metering object therethrough, and said secondbottom plate forming an opening/closing member mounted on said load sideof said load cell to open/close said discharge port, (c) an air cylindermounted on said load side of said load cell to drive a piston in ahorizontal direction to actuate said opening/closing member, (d) twoflexible tubes connected between said base body and said air cylinder tosupply and discharge air, and (e) an exhaust unit to discharge airdischarged from said air cylinder to an outside of said base body.
 25. Acombined metering apparatus according to claim 24, furthercomprising:first opening/closing drive unit related to said plurality ofpool hoppers to move said first bottom plate in a first direction toclose said lower open end portion of said first cylindrical body and tomove said first bottom plate in a second direction opposite to the firstdirection to open said lower open end portion of said first cylindricalbody, and a second opening/closing drive unit including said aircylinder and related to said plurality of metering hoppers to move saidsecond bottom plate in the second direction to close said lower endportion of said second cylindrical body and to move said second bottomplate in the first direction to open said lower end portion of saidsecond cylindrical body.
 26. A combined metering apparatus according toclaim 25, further comprising a control unit for controlling said firstand second opening/closing drive units such that movement of said secondbottom plate in the second direction and movement of said first bottomplate in the second direction are almost in synchronism with each other.27. A combined metering apparatus according to claim 24, wherein:saidupper open end portion of said second cylindrical body is larger thansaid upper open end portion of said first cylindrical body, and saidsecond cylindrical body is arranged, within a range where said upperopen end portion of said second cylindrical body and said lower open endportion of said first cylindrical body overlap vertically, close to aside toward which said first bottom plate is opened.
 28. A combinedmetering apparatus according to claim 24, wherein each of said first andsecond bottom plates has two end portions that are supported by a pairof guide shafts supported substantially horizontally and parallel toeach other, and is slidably moved in a lengthwise direction of said pairof guide shafts upon reception of a force of a drive shaft of a driveunit.
 29. A combined metering apparatus according to claim 28, whereineach of said first and second bottom plates hasa first bearing portionformed into a groove in a side surface side of one end portion in orderto laterally receive said drive shaft, thereby transmitting the force ofsaid drive shaft to said bottom plate, a second bearing portion formedinto a groove in a lower surface side of said one end portion in orderto receive one of said pair of guide shafts from below, therebyregulating movement of said bottom plate in a direction perpendicular tothe lengthwise direction of said guide shafts, and each of said firstand second bottom plates is supported by said pair of guide shafts suchthat said drive shaft is engaged with said first bearing portion, one ofsaid pair of guide shafts is engaged with said second bearing portion,and the other one of said guide shafts is abutted against a lowersurface of the other end portion.
 30. A combined metering apparatusaccording to claim 24, wherein each of said first and second cylindricalbodies has a tilted surface at an outer circumferential portion of alower end thereof, said tilted surface being formed such that a heightthereof from a lower end face is gradually increased toward an outerside, and said tilted surface is located on a side toward which each ofsaid first and second bottom plates is moved to open said lower open endportion.
 31. A combined metering apparatus comprising:a supply forsupplying target metering objects; a plurality of pool hoppers forseparately receiving the target metering objects supplied by saidsupply, said plurality of pool hoppers being arranged in a horizontaldirection in sets, each pool hopper including a first cylindrical bodyhaving upper and lower open end portions, and a first bottom plateslidable to selectively open/close said lower open end portion of saidfirst cylindrical body; a plurality of metering hoppers for receivingthe target metering objects separately falling from said plurality ofpool hoppers, said plurality of metering hoppers being arranged in setson a lower stage side of said plurality of pool hoppers to correspondthereto, each of the metering hoppers including a second cylindricalbody having upper and lower open end portions, and a second bottom plateslidable to selectively open/close said lower open end portion of saidsecond cylindrical body; a plurality of metering devices provided inassociation with said plurality of metering hoppers to separately meterthe target metering objects received in said plurality of meteringhoppers and to output electric signals, each of said metering devicesincluding:(a) a base body, (b) a load cell having a mount side mountedon said base body, with said second cylindrical body mounted on a loadside of said load cell and having a receiving port at the upper endportion thereof to receive the target metering object and a dischargeport at the lower end portion thereof to discharge the target meteringobject therethrough, and said second bottom plate forming anopening/closing member mounted on said load side of said load cell toopen/close said discharge port, and (c) a drive portion mounted on saidload side of said load cell to drive said opening/closing membersubstantially horizontally; a selecting unit for selecting a combinationof the target metering objects providing a predetermined metered valuein said plurality of metering hoppers in accordance with the electricsignals from said plurality of metering devices; a device for collectingand discharging the target metering objects falling from correspondingones of said plurality of metering hoppers in accordance with thecombination of the target metering objects selected by said selectingunit; a first opening/closing drive unit related to said plurality ofpool hoppers to move said first bottom plate in a first direction toclose said lower open end portion of said first cylindrical body and tomove said first bottom plate in a second direction opposite to the firstdirection to open said lower open end portion of said first cylindricalbody; and a second opening/closing drive unit forming said drive portionand related to said plurality of metering hoppers to move said secondbottom plate in the second direction to close said lower open endportion of said second cylindrical body and to move said second bottomplate in the first direction to open said lower open end portion of saidsecond cylindrical body.
 32. A combined metering apparatus according toclaim 31, further comprising a control unit for controlling said firstand second opening/closing drive units such that movement of said secondbottom plate in the second direction and movement of said first bottomplate in the second direction are almost in synchronism with each other.33. A combined metering apparatus according to claim 31, wherein:saidupper open end portion of said second cylindrical body is larger thansaid upper open end portion of said first cylindrical body, and saidsecond cylindrical body is arranged, within a range where said upperopen end portion of said second cylindrical body and said lower open endportion of said first cylindrical body overlap vertically close to aside toward which said first bottom plate is opened.
 34. A combinedmetering apparatus according to claim 31, wherein each of said first andsecond bottom plates has two end portions that are supported by a pairof guide shafts supported substantially horizontally and parallel toeach other, and is slidably moved in a lengthwise direction of said pairof guide shafts upon reception of a force of a drive shaft of a driveunit.
 35. A combined metering apparatus according to claim 34, whereineach of said first and second bottom plates has:a first bearing portionformed into a groove in a side surface side of one end portion in orderto laterally receive said drive shaft, thereby transmitting the force ofsaid drive shaft to said bottom plate, and a second bearing portionformed into a groove in a lower surface side of said one end portion inorder to receive one of said pair of guide shafts from below, therebyregulating movement of said bottom plate in a direction perpendicular tothe lengthwise direction of said guide shafts, and each of said firstand second bottom plates is supported by said pair of guide shafts suchthat said drive shaft is engaged with said first bearing portion, one ofsaid pair of guide shafts is engaged with said second bearing portion,and the other one of said guide shafts is abutted against a lowersurface of the other end portion.
 36. A combined metering apparatusaccording to claim 31, wherein each of said first and second cylindricalbodies has a tilted surface at an outer circumferential portion of alower end thereof, said tilted surface being formed such that a heightthereof from a lower end face is gradually increased toward an outerside, and said tilted surface is located on a side toward which each ofsaid first and second bottom plates is moved to open said lower open endportion.
 37. A combined metering apparatus according to claim 31,wherein each of said plurality of metering means includes, when saiddrive portion comprises an air cylinder,a flexible tube connected tosupply air from said base body to said air cylinder, and an exhaust unitmounted to said load side of said load cell to direct air dischargedfrom said air cylinder almost horizontally.
 38. A combined meteringapparatus comprising:a supply for supplying target metering objects; aplurality of pool hoppers for separately receiving the target meteringobjects supplied by said supply means, said plurality of pool hoppersbeing arranged in a horizontal direction in sets, each pool hopperincluding a first cylindrical body having upper and lower open endportions, and a first bottom plate slidable to selectively open/closesaid lower open end portion of said first cylindrical body; a pluralityof metering hoppers for receiving the target metering objects separatelyfalling from said plurality of pool hoppers, said plurality of meteringhoppers being arranged in sets on a lower stage side of said pluralityof pool hoppers to correspond thereto, each of the metering hoppersincluding a second cylindrical body having upper and lower open endportions, and a second bottom plate slidable to selectively open/closesaid lower open end portion of said second cylindrical body; a pluralityof metering devices provided in association with said plurality ofmetering hoppers to separately meter the target metering objectsreceived in said plurality of metering hoppers and to output electricsignals, each of said metering devices including:(a) a base body, (b) aload cell having a mount side mounted on said base body, with saidsecond cylindrical body mounted on a load side of said load cell andhaving a receiving port at the upper end portion thereof to receive thetarget metering object and a discharge port at the lower end portionthereof to discharge the target metering object therethrough, and saidsecond bottom plate forming an opening/closing member mounted on saidload side of said load cell to open/close said discharge port, and (c) adrive portion mounted on said load side of said load cell to drive saidopening/closing member substantially horizontally; a selecting unit forselecting a combination of the target metering objects providing apredetermined metered value in said plurality of metering hoppers inaccordance with the electric signals from said plurality of meteringdevices; a device for collecting and discharging the target meteringobjects falling from corresponding ones of said plurality of meteringhoppers in accordance with the combination of the target meteringobjects selected by said selecting unit; wherein each of said pluralityof metering devices includes, when said drive portion comprises an aircylinder,(a) two flexible tubes connected between said base body andsaid air cylinder to supply and discharge air, and (b) an exhaust unitprovided to discharge air discharged from said air cylinder to anoutside of said base body; a first opening/closing drive unit related tosaid plurality of pool hoppers to move said first bottom plate in afirst direction to close said lower open end portion of said firstcylindrical body and to move said first bottom plate in a seconddirection opposite to the first direction to open said lower open endportion of said first cylindrical body, and a second opening/closingdrive unit forming said drive portion and related to said plurality ofmetering hoppers to move said second bottom plate in the seconddirection to close said lower open end portion of said secondcylindrical body and to move said second bottom plate in the firstdirection to open said lower open end portion of said second cylindricalbody.
 39. A combined metering apparatus according to claim 38, furthercomprising a control unit for controlling said first and secondopening/closing drive units such that movement of said second bottomplate in the second direction and movement of said first bottom plate inthe second direction are almost in synchronism with each other.
 40. Acombined metering apparatus according to claim 38, wherein:said upperopen end portion of said second cylindrical body is larger than saidupper open end portion of said first cylindrical body, and said secondcylindrical body is arranged, within a range where said upper open endportion of said second cylindrical body and said lower open end portionof said first cylindrical body overlap vertically, close to side towardwhich said first bottom plate is opened.
 41. A combined meteringapparatus according to claim 38, wherein each of said first and secondbottom plates has two end portions that are supported by a pair of guideshafts supported substantially horizontally and parallel to each other,and is slidably moved in a lengthwise direction of said pair of guideshafts upon reception of a force of a drive shaft of a drive unit.
 42. Acombined metering apparatus according to claim 41, wherein each of saidfirst and second bottom plates has:a first bearing portion formed into agroove in a side surface side of one end portion in order to laterallyreceive said drive shaft, thereby transmitting the force of said driveshaft to said bottom plate, a second bearing portion, formed into agroove in a lower surface side of said one end portion in order toreceive one of said pair of guide shafts from below, thereby regulatingmovement of said bottom plate in a direction perpendicular to thelengthwise direction of said guide shafts, and each of said first andsecond bottom plates is supported by said pair of guide shafts such thatsaid drive shaft is engaged with said first bearing portion, one of saidpair of guide shafts is engaged with said second bearing portion, andthe other one of said guide shafts is abutted against a lower surface ofthe other end portion.
 43. A combined metering apparatus according toclaim 38, wherein each of said first and second cylindrical bodies has atilted surface at an outer circumferential portion of a lower endthereof, said tilted surface being formed such that a height thereoffrom a lower end face is gradually increased toward an outer side, andsaid tilted surface is located on a side toward which each of said firstand second bottom plates is moved to open said lower open end portion.